CN109127655B - Method and system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag - Google Patents

Method and system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag Download PDF

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CN109127655B
CN109127655B CN201810867522.XA CN201810867522A CN109127655B CN 109127655 B CN109127655 B CN 109127655B CN 201810867522 A CN201810867522 A CN 201810867522A CN 109127655 B CN109127655 B CN 109127655B
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刘恩辉
吕燊燊
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Xiangtan University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
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Abstract

The invention relates to a method and a system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon residues. The conversion method comprises the steps of converting sodium-containing compounds in the aluminum electrolysis waste carbon residue into soluble sodium compounds without fluorine, converting fluorine-containing compounds into insoluble and harmless mineral fluorine compounds, and oxidizing cyanogen-containing compounds into harmless gases by using a conversion agent through mechanochemical conversion reaction in a conversion mill, thereby completely removing the harm of fluoride and cyanide in the aluminum electrolysis waste carbon residue. The conversion system is sequentially connected with waste carbon residue crushing equipment, grinding equipment, a conversion mill, a stirring reactor and solid-liquid separation equipment, the solid-liquid separation equipment is directly connected with concentration or crystallization equipment and drying or heat treatment equipment, and the drying or heat treatment equipment is connected with crushing equipment. The method has the advantages of simple process, easy large-scale production, low production cost, no three-waste pollution and environmental friendliness, and can realize the harmless and recycling treatment target of the aluminum electrolysis waste carbon slag.

Description

Method and system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag
Technical Field
The invention relates to a method and a system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon residues, belonging to the technical field of harmless and resource utilization of solid wastes in the electrolytic aluminum industry.
Background
The aluminum electrolysis capacity is about 4500 ten thousand tons, the actual yield exceeds 3600 ten thousand tons and accounts for more than 50 percent of the global aluminum electrolysis capacity in China by 2017. In the production of electrolytic aluminum, various waste carbon residues are produced, including anode waste carbon residues (including fire hole carbon residues, anode ash, anode residues, anode paste and the like), cathode waste carbon residues, electrolytic cell overhaul waste cathode carbon blocks, waste ramming paste, waste carbon residues formed when a new electrolytic cell is prebaked, and the like. On average, 0.48 ton of carbon anode is needed for producing 1 ton of electrolytic aluminum, anode waste carbon residue is generated by carbon which is peeled off from the carbon anode, falls into molten electrolyte and floats on the surface of the carbon anode in the production process of the electrolytic aluminum, and most of the carbon residue can be combusted and oxidized on the surface of the electrolyte to form CO2The gas is consumed, but a small part of waste carbon particles floating on the surface of the electrolyte and not combusted are fished out to form anode waste carbon residue. In the aluminum electrolysis production process, the carbon cathode expands due to the permeation of fluorine-containing salt, and further causes the damage and the scrapping of the electrolytic cell; the aluminum cell is generally stopped after about 4 to 6 years of useAnd (4) overhauling, namely taking out all the waste tank lining materials (called as overhaul slag for short), wherein the waste cathode carbon blocks account for about 50% of the overhaul slag. The waste carbon residue is solid waste inevitable in the production process of electrolytic aluminum, and 10-30 kg of waste carbon residue is generated when 1 ton of electrolytic aluminum is produced. The electrolytic aluminum waste carbon slag is specified as dangerous solid waste (category: HW48) in the national records of dangerous waste, and waste tank linings are listed in the national records of dangerous waste HW32 inorganic fluoride waste and HW33 inorganic cyanide waste. Fluorine-containing electrolyte and cyanogen-containing compound in the aluminum electrolysis waste carbon residue have solubility and reactivity, and the fluorine-containing and cyanogen-containing compound can cause great harm to the health and growth of human beings, animals and plants when entering the environment.
The fluorine-containing electrolyte and the carbon material in the aluminum electrolysis waste carbon residue are valuable resources. Therefore, how to thoroughly remove the harm of fluorine and cyanogen compounds in the aluminum electrolysis waste carbon residue and realize harmlessness and resource recycling of the aluminum electrolysis waste carbon residue is an industry difficult problem which needs to be overcome urgently.
CN106745137A, CN106077038A, CN106077040A, CN106587122A, CN101817521A, CN106086938A and CN105821445A of the invention propose to treat aluminum electrolysis waste cathode carbon or aluminum electrolysis waste by adopting an alkaline leaching or ultrasonic-assisted flotation and pressurization alkaline leaching method, crush the waste, carry out flotation and magnetic separation to obtain carbon powder A, add alkali liquor to the carbon powder A to dissolve fluoride, add CO into the solution to dissolve fluoride2Separating out cryolite, and performing secondary flotation on the carbon powder A to obtain high-purity carbon powder.
The invention CN106077037A, CN106077036A, CN106180118A and CN101984984A in China propose to treat the aluminum electrolysis waste cathode carbon or overhaul residues by adopting an acid treatment or ultrasonic-assisted flotation pressurization acid treatment method.
The invention CN107162061A of China proposes a method of combining alkali leaching, acid leaching and fly ash to carry out harmless treatment and resource utilization on the waste cathode carbon of the aluminum electrolytic cell.
Chinese inventions CN106064813A and CN105964659A propose that waste cathode carbon powder is subjected to heat preservation and decyanation at 200-400 ℃, decyanation materials are subjected to flotation separation to obtain carbon slag and electrolyte slag, and the electrolyte slag is heated at 550-800 ℃ to remove carbon impuritiesElectrolyte powder is obtained, soluble substances in the carbon residue are removed through alkaline leaching to obtain carbon powder with high purity, and CO is introduced into alkaline leaching filtrate2Separating out the mixture of cryolite and aluminum hydroxide.
Chinese invention CN105772486A proposes to soak the waste cathode carbon powder in aluminum electrolytic cell with water, leach soluble cyanide, and add hydrogen peroxide, stabilizer (selected from citric acid, tartaric acid, ethylenediamine tetraacetic acid, aminotrimethylene phosphonic acid, polyacrylic acid, maleic acid, borax, ammonium carbonate, ammonium bicarbonate, ammonium acetate and ammonium citrate) and catalyst (selected from ZnO, CuO and Fe)3O4、WO3Middle) and then reacted at 30-70 ℃ to decompose cyanide oxidation products into CO2、NH3A gas.
The invention CN105728440A in China provides an aluminum cell overhaul residue harmless treatment system and a treatment method, the system comprises a leaching bin and a reaction bin which is connected with the leaching bin and is used for carrying out cyanogen and fluorine removal treatment, the cyanogen removal agent is one or more of sodium chlorate, bleaching powder, hydrogen peroxide, bleaching powder essence and chlorine dioxide, and the fluorine removal agent is one or more of calcium chloride, aluminum chloride, magnesium chloride, calcium hydroxide and calcium oxide.
Chinese invention CN106166560A proposes a method for treating waste cathode carbon blocks, which comprises leaching the overhaul residues of an electrolytic cell with water to obtain leached cathode carbon blocks and leachate, reacting the leachate with quicklime, lime milk, carbide slag or calcium chloride, and then performing liquid-solid separation, returning the filtrate to the leaching step for recycling, and stacking filter cakes or using the filter cakes as raw materials for preparing calcium fluoride.
Chinese invention CN107313073A proposes a method for heap leaching treatment of waste cathode linings of aluminum electrolysis cells, which comprises the steps of respectively crushing and screening insulating bricks, castable, anti-seepage materials and carbon materials in waste cathode linings separated from overhaul tank slag of the aluminum electrolysis cells, mixing the crushed waste insulating bricks, castable and anti-seepage materials, and then treating the mixture together, and treating the carbon materials separately; pre-leaching, heap leaching and washing the crushed materials, removing cyanogen by using hydrogen peroxide, and then performing filter pressing; introducing CO into the filtrate2The gas is subjected to carbonation and neutralization treatment and then concentrated, crystallized and recovered to obtain the productFluoroNaHCO 23And fluorine-containing Na2CO3NaF.
The invention CN105645449A provides a system and a method for recycling cryolite from waste carbon slag of an aluminum electrolysis cell, wherein a treatment system comprises a leaching bin, a flotation device and a solid-liquid separation device, and the cryolite in the waste carbon slag is recycled by flotation.
The invention CN103803620A of China provides a production process for refining cryolite from electrolytic aluminum slag, which comprises the steps of ball-milling the electrolytic slag into powder, carrying out three-stage flotation on the powder, and carrying out flotation separation to obtain the cryolite and carbon powder respectively.
The invention CN103949459A of China provides a method for recycling electrolyte for producing aluminum by using electrolytic aluminum carbon slag and recycling carbon, which comprises the steps of pretreatment, flotation separation, preparation and post-treatment, wherein, the pretreated electrolytic waste carbon material is separated to obtain a bottom flow product and a foam product, the bottom flow product is filtered, decarbonized and crushed to obtain electrolyte, and the foam product is filtered, pressed and dried to obtain carbon powder.
The invention of China CN104499000A provides a mineral processing method of electrolytic aluminum carbon slag, which comprises the steps of crushing and grinding the carbon slag, adding water, a collecting agent and a foaming agent into the carbon slag to prepare ore pulp, carrying out flotation on the ore pulp, taking the foam product as carbon powder by flotation, and filtering, drying and calcining the material without the foam product to obtain the cryolite product.
The invention CN103949460A provides a device and a method for producing regenerated electrolyte by aluminum electrolysis carbon residue, which realize the comprehensive utilization of the aluminum electrolysis carbon residue by the production processes of carbon residue crushing, ball milling, flotation, drying, regenerated electrolyte refining and tail gas treatment.
The invention CN105239097A in China provides a water quenching and sorting treatment method of aluminum electrolysis anode carbon slag, which comprises the steps of water quenching of thermal-state carbon slag, classification of water-quenched slag, wet grinding of carbon slag and flotation, and carbon-rich products and electrolyte-rich products are respectively obtained.
The invention CN106917110A of China provides a method for separating and recycling carbon slag and electrolyte in waste anode slag of electrolytic aluminum, and the separation and recycling of carbon and electrolyte are realized by adopting a method combining high-temperature melting and flotation.
The invention CN102992300A of China provides a high-temperature calcination method of waste anode slag of electrolytic aluminum, which comprises the steps of crushing and ball-milling the waste anode slag of electrolytic aluminum, separating carbon powder through flotation, removing iron-containing impurities through magnetic separation, and calcining the carbon powder at 1700-1900 ℃ to remove fluoride and sulfur in the carbon powder to obtain high-purity carbon powder; fluoride salts and sulfur products are separately recovered from the gas phase.
Chinese invention CN1253369C provides a method for recovering fluoride salt in aluminum electrolysis anode carbon slag, which comprises adding alumina into carbon slag, roasting at 650-930 deg.C to completely burn carbon, and absorbing tail gas with alumina to obtain fluoride salt containing alumina.
The invention CN101063215A of China provides a method for extracting electrolyte from anode carbon slag of aluminum electrolysis, which comprises the steps of adding a binder into the anode carbon slag, uniformly mixing, pressing into blocks, roasting at 650-800 ℃ to completely burn combustible substances, and returning the obtained roasted product with the electrolyte content of more than 98% to an aluminum electrolysis cell for use.
The invention CN101255566A of China provides a method for recycling electrolyte in aluminum electrolysis carbon slag, dispersant calcium fluoride and fuel coal are added into anode carbon slag, roasting treatment is carried out at 650-800 ℃, and the obtained electrolyte is returned to an aluminum electrolysis cell for use.
The invention CN103831285A provides an aluminum electrolysis waste carbon residue harmless treatment system and a method thereof, comprising a heating furnace, a heating circulation device and a tail gas purification device. And (3) treating the carbon slag in a heating furnace at 1250-1350 ℃ for 7-8 h, discharging decomposed electrolyte in the hearth through a discharge hole, and discharging carbon powder through a slag outlet.
The invention CN102011148A of China provides a method for harmless treatment of aluminum electrolysis anode carbon slag and electrolyte recovery, the anode carbon slag is smelted in a high-temperature furnace at 800-1500 ℃, and after complete combustion of carbon materials, electrolyte completely forms electrolyte melt; the flue gas generated in the smelting process is connected into an electrolysis series flue gas purification system, fluoride gas is absorbed by aluminum oxide and then returns to the electrolytic cell, and the electrolyte melt directly enters the electrolytic cell for use.
The invention CN107285354A of China provides a low-temperature melting permeation continuous separation method of aluminum industry carbon hazardous waste and an obtained product, and comprises the steps of carrying out crushing and deironing pretreatment on the carbon hazardous waste; performing low-temperature electric calcination on the pretreated carbon hazardous waste at 1050-1200 ℃ to enable fluoride salt to be molten into liquid and to be subjected to infiltration separation; and (4) permeating and removing impurities from the residual low-fluorine carbon particles, then feeding the low-fluorine carbon particles into a high-temperature electric calcining furnace, and performing high-temperature electric calcining to obtain a high-purity carbon product.
The invention CN106629606A in China provides a method for separating fluoride salt and carbon in carbon slag of aluminum electrolysis, a vacuum distillation furnace with the temperature of 800-1200 ℃ and the vacuum degree of 1-100 Pa is adopted to separate fluoride salt and carbon in the carbon slag, the separated fluoride salt returns to an electrolytic cell, and the carbon returns for utilization.
Chinese CN105463506A provides a method for separating and recovering electrolyte and carbon in aluminum electrolyte anode carbon slag, which comprises the steps of placing the aluminum electrolyte anode carbon slag in a smelting furnace, heating and melting at 700-1600 ℃ in the atmosphere of nitrogen or inert gas to obtain an aluminum electrolyte anode carbon slag melt, and blowing the melt to achieve the purpose of separating the electrolyte and the carbon in the aluminum electrolyte anode carbon slag and obtain high-quality electrolyte and carbon products.
The invention CN107604383A of China provides a method for extracting electrolyte from carbon slag by a smelting method, which comprises the steps of heating the carbon slag in a smelting furnace to 1250-1300 ℃, smelting the electrolyte in the carbon slag into liquid, floating carbon on the surface of electrolyte liquid, discharging the electrolyte after the floating carbon is removed, and returning the electrolyte to the production of electrolytic aluminum for use after cooling.
The invention CN106247340A of China provides a method and a device for processing electrolytic aluminum carbon slag, wherein the processing device comprises a roasting chamber and a combustion chamber, the temperature of the roasting chamber is raised to 1000-1100 ℃, electrolyte in the carbon slag is layered with the carbon slag, and a separating agent is added to separate the electrolyte from the carbon slag; the separated carbon slag enters a combustion chamber to be burnt out, and the electrolyte is recovered.
The Chinese invention CN106517209A provides a method for processing waste cathodes of aluminum cell liners, which comprises the steps of adding carbon materials and quartz sand into the waste cathodes of the aluminum cell liners, carrying out high-temperature carbothermic reduction to generate SiC, forming melt sinking by cryolite and carrying out solid-liquid separation on SiC, evaporating fluoride salt in furnace gas and carrying out gas-solid separation on the generated SiC to respectively prepare SiC, the cryolite melt and fluoride salt.
The invention CN107904621A of China proposes a regeneration treatment method of waste cathode carbon blocks of an aluminum electrolytic cell, and the main treatment process comprises crushing, screening, toxicity inhibition, batching and pressure-controlled heat treatment. After the aluminum cell waste cathode carbon block material is crushed and screened, adding toxicity inhibitors such as hydrogen peroxide, potassium permanganate, hypochlorite and the like, then adding carbon materials such as anthracite, calcined petroleum coke, waste anode carbon blocks, anode scraps and the like as furnace entering raw materials, placing the raw materials in a resistance furnace for heat treatment under the conditions of normal pressure (1200-1800 ℃) or controlled pressure (1000-1600 ℃ and 0.01-0.5 atm), cooling and crystallizing the volatilized fluoride in the flue gas for recovery, and enabling the carbon content of the furnace slag to reach 99% and being capable of being used for producing various carbon products. The invention CN107904622A of China treats the waste side lining silicon carbide material of the aluminum electrolytic cell in a similar way.
The invention CN106147910A of China provides a system and a method for producing high-graphite anthracite by using electrolytic aluminum waste cathode carbon blocks, wherein the system comprises a crushing and screening unit, an automatic feeding unit, an ultrahigh temperature calcination unit, a finished product cooling unit and a packaging unit. The graphitization degree of the finished product material is more than or equal to 90% by adopting a method of improving the graphitization degree of the waste cathode carbon block of the electrolytic aluminum under the ultra-high temperature state of 2300-3000 ℃, and the volatile components contained in the raw materials can be completely decomposed under the ultra-high temperature state.
From the prior technical achievements, the harmless and resource treatment and utilization of the aluminum electrolysis waste carbon residue are divided into two categories, namely wet treatment of aqueous solution and fire treatment at high temperature. The wet treatment also involves water washing (leaching), alkali method, acid-alkali combination method and flotation process, mainly aims at recovering electrolyte and carbon material, and adopts oxidant to decompose cyanide into harmless gas substance in the wet treatment. The pyrogenic process treatment technology mainly aims at harmlessness, or can effectively utilize the heat value resource of the waste carbon slag based on the carbon content of more than 50 percent in the waste carbon slag; or the electrolyte is melted, permeated and separated to be recovered; or converting the fluoride into HF and then carrying out absorption conversion utilization; or converting the electrolyte into harmless and insoluble fluorine mineral by adding a conversion aid; or the carbon material and the electrolyte are respectively recycled by adopting a high-temperature vacuum technology. In the pyrogenic process, cyanide-containing compounds are oxidatively decomposed at high temperatures into harmless gaseous substances.
From the prior technical results, the wet treatment and the fire treatment of the aluminum electrolysis waste carbon residue still have a plurality of problems which need to be solved urgently.
The current wet processing technology has at least the following main problems: firstly, a large amount of generated salt-containing and fluorine-containing wastewater is not effectively treated, so that the problem of secondary pollution is caused; generated H2、CH4、NH3The gas is not controlled and utilized and the HF produced causes serious pollution. Secondly, the recovered electrolysis and carbon materials have too high impurity content to be directly utilized. Thirdly, the process route is complicated, the technology is complex, the equipment corrosion is serious, and the treatment cost is too high. Fourthly, the difficulty of controlling the process parameters is high due to the influence of factors such as the difference of the capacity and the age of the electrolytic aluminum tank, the fluctuation of components, the granularity of powder and the like.
The current fire treatment technology has at least the following main problems: first, the off-gas that produces large amounts of entrained HF and dust needs to be treated. Second, the electrolyte salt recovery does not remain completely in the carbonaceous material or slag requiring further treatment. Thirdly, the low-melting point electrolyte salt is melted and agglomerated in the furnace, so that the residual quantity of the carbon material is large due to incomplete oxidation and combustion, and the melting and agglomeration in the furnace cause the deterioration of the production working condition and the poor production stability. Fourth, the reaction mass is difficult to achieve uniform mixing at the molecular level, resulting in incomplete conversion reactions. Fifthly, the equipment is seriously corroded and the energy consumption for treatment is high.
Disclosure of Invention
In order to solve the technical problems, the invention provides a method and a system for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag. The invention has the characteristics of convenient control of production process, easy industrial stable production, low process cost, no three-waste pollution, no equipment corrosion and the like.
The invention is realized by the following technical scheme:
a method for converting sodium-containing and fluorine-containing compounds in waste carbon residue from aluminum electrolysis utilizes a conversion agent to convert sodium-containing compounds in the waste carbon residue from aluminum electrolysis into soluble sodium compounds without fluorine, fluorine-containing compounds into insoluble and harmless mineral fluorine compounds, and cyanogen-containing compounds into harmless N by oxidation through mechanochemical conversion reaction in a conversion mill2Or NH3And CO2Thereby thoroughly removing the harm of fluoride and cyanide in the waste carbon residue from aluminum electrolysis; the conversion system comprises a crushing, grinding, screening and homogenizing system, a mechanochemical conversion reaction and solid-liquid separation system, a concentration and crystallization system, a drying and heat treatment system, a tail gas collecting and absorbing system, an analysis and test system and a packaging and storage system. The method has the characteristics of simple process, easy large-scale production, low production cost, no three-waste pollution, environmental friendliness and the like. The invention can realize the treatment targets of harmlessness, reclamation and final polarization of the aluminum electrolysis waste carbon slag.
A method for converting sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag comprises the following partial or all steps (the following steps are expressed for convenience and do not directly show the precedence relationship, and the included steps specifically comprise which parts are subject to the logical description or logical relationship in the characters):
(1) crushing, grinding and homogenizing the aluminum electrolysis waste carbon slag to obtain waste carbon slag powder with the particle size less than or equal to 200 mu m; analyzing and determining the mole number or mass of sodium and fluorine in the waste carbon residue powder per unit mass; analyzing and determining CN in unit mass of waste carbon residue powder-The number of moles or mass of ions;
adding the grinding body into the conversion mill, and then carrying out air evacuation or N on the conversion mill2Replacing, namely adding the measured waste carbon residue powder into a conversion mill, controlling the mass ratio of the waste carbon residue powder to a grinding body to be 1 (0.2-10), adding the measured water into the conversion mill, and controlling the solid-liquid mass ratio of the waste carbon residue powder to the water to be 1 (1-10);
adding a conversion agent into a conversion mill according to the amount of 1-3 times of the stoichiometric ratio of the sodium and fluorine-containing compounds in the waste carbon residue powder to the corresponding products in the chemical reaction, or according to the amount of 5-80% of the mass of the waste carbon residue powder;
adding a grinding aid into a conversion mill according to the mass of 0-1% of the waste carbon residue powder;
(2) after the step (1) is finished, starting the conversion mill, and controlling the rotation speed of the conversion mill to be 10-1000 rpm and the conversion temperature to be 10-110 ℃; in the conversion process, the slurry is sampled and analyzed and checked in batches at regular time until Na in the solid phase of the slurry+The ion content meets the enterprise standard and the soluble F-Stopping the conversion grinding when the ion content meets the national emission standard;
(3) after the step (2) is finished, transferring the slurry into a stirring reactor (a reaction kettle, a reaction tank or a reaction tank) for gel breaking and aging treatment, wherein the temperature is controlled to be 60-150 ℃, and the treatment time is 0.5-5 h;
(4) carrying out solid-liquid separation on the slurry obtained in the step (3) by adopting a filtering or centrifugal separation mode, repeatedly carrying out dispersion washing and solid-liquid separation on a water-containing solid-phase substance in a conversion mill or a stirring reactor (a reaction kettle or a reaction tank) by taking water as a washing agent according to the solid-liquid mass ratio of 1 (1-10) for a plurality of times until the content of soluble ions in the solid-phase substance meets the enterprise standard, combining separation liquids, and respectively obtaining a mixture of wet fluorine-containing mineral substances and carbon, namely the water-containing solid-phase substance and a dilute solution of the mixture;
(5) drying or carrying out heat treatment on the aqueous solid phase obtained in the step (4) at the temperature of 80-300 ℃ for 1-10 h, and then crushing to obtain a mixed powder material of a fluorine-containing mineral substance and carbon, wherein the average particle size of the mixed powder material is less than or equal to 20 microns, and the mixed material can be sold as a commodity or further separated and purified to obtain a high-quality carbon material and a fluoride mineral substance raw material;
placing the mixed powder material containing the fluorine-containing mineral substances and carbon in an air atmosphere and a high-temperature furnace at the temperature of 700-1200 ℃ for calcining for 0.5-5 h, wherein the carbon component is completely oxidized and combusted, and the residue of the mixed powder material is a mixture containing the fluorine-containing mineral substances;
(6) concentrating or crystallizing the mixture dilute solution obtained in the step (4) to obtain a mixture concentrated solution or a solid-phase mixture, or further separating and purifying Na, K, Li, Al, Mg and Ca compounds in the mixture to obtain a series of compound raw materials with higher quality and value;
(7) according to CN in waste carbon slag powder-Conversion of ions to N2Or NH3And CO2In an amount of 1 to 5 times of the stoichiometric ratio of the chemical reaction, or in an amount of 0.1 to 10 percent of the mass of the waste carbon residue powder, adding a cyanide conversion agent into the mixture obtained in the step (2), the step (3) or the step (6) to oxidize and convert the cyanide-containing compound into harmless N2Or NH3And CO2The analysis and check are carried out on the transformation system in batches and at regular time until CN in the system-The conversion reaction is stopped when the ion content meets the national emission standard;
(8) the NH generated in the step (2) or the step (3) or the step (6)3、CO2、H2And (4) carrying out absorption conversion and drying on the O gas, and collecting the generated reducing gas or directly oxidizing and burning the reducing gas.
The aluminum electrolysis waste carbon residue refers to all solid wastes containing carbon components (including graphitized C and non-graphitized C) generated in the production of electrolytic aluminum.
Al and Al exist in the aluminum electrolysis waste carbon slag4C3AlN, Na, etc., and combustible gases (including H) generated by the reaction taking part in the conversion reaction2、CH4、NH3Etc.) is the reducing gas in the step (8).
In the conversion mill, high-energy mechanical force synchronously acts on the mechanochemical conversion reaction of the sodium-containing compound and the fluorine-containing compound, so that solid particles are continuously ground, milled and converted, reactants and products are continuously updated and stripped from carbon particles, and the conversion reaction is quickly and completely finished.
Further, in all the steps, the pH is controlled to be not less than 6, no protonic acid substance is used, and the conversion agent of the sodium-containing compound and the fluorine-containing compound, the cyanide conversion agent and the grinding aid substance are used without chlorine elements.
Further, the main elements of the waste carbon slag powder are more than two of C (including graphitized C and non-graphitized C), Na, F, Al, Ca, O, N, Li, Mg, Si, K and Fe.
Further, the sodium-containing compound comprises NaF and Na3AlF6、NaCN、Na4[Fe(CN)6]Two or more of them.
Further, the fluorine-containing compound comprises NaF and Na3AlF6、AlF3、LiF、CaF2、MgF2And KF.
Further, the conversion agent of the sodium-containing compound and the fluorine-containing compound comprises one or more than two of oxides, hydroxides, sulfates, nitrates, carbonates, acetates and citrates corresponding to the elements of Ca, Al, Mg, Sr, Ba, La and Ce.
After the conversion by the conversion agent, the sodium-containing compounds in the waste carbon residue are converted into corresponding soluble sodium compounds without fluorine, including NaOH and Na2SO4、NaNO3、NaOAc、Na2CO3、Na3C6H5O7、Na2AlO4、Na[Al(OH)6]2(OH)3、NaAlSi2O6、Na2(H2SiO4)·7H2O、Na6Si8O19、Na2Al2SiO6、Na2Si2O5、Na2SiO3One or more than two of them.
After conversion by the conversion agent, the fluorine-containing compounds in the waste carbon residue are converted into corresponding insoluble and harmless mineral fluorides including CaF2、MgF2、AlF3、SrF2、BaF2、CaF2、LaF3、CeF3、CeF4One or more than two of them.
Further, the cyanide conversion agent comprises Na2CO3·1.5H2O2、K2CO3·1.5H2O2、Na2O2、K2O2、CaO2、SrO2、BaO2、H2O2、(NH4)2S2O8、Na2S2O8、K2S2O8、KMnO4、O2、O3One or more than two of them.
Further, the grinding aid comprises one or more of polymeric polyol, polymeric alcohol amine, triisopropanolamine, ethylene glycol, propylene glycol, glycerol, diethylene glycol, triethanolamine, amide, stearic acid, oleic acid, sodium hexametaphosphate and sodium stearate.
Furthermore, the transforming agent and the grinding aid are added in a solid, aqueous solution or gas state in a one-time adding mode, a batch adding mode or a continuous adding mode.
A conversion system for sodium-containing and fluorine-containing compounds in aluminum electrolysis waste carbon slag comprises waste carbon slag crushing equipment, grinding equipment, a conversion mill, a stirring reactor and solid-liquid separation equipment which are sequentially connected, wherein the solid-liquid separation equipment is directly connected with concentration or crystallization equipment and drying or heat treatment equipment, and the drying or heat treatment equipment is connected with the grinding equipment.
Further, the device also comprises a condensing device which is connected with the concentrating or crystallizing device.
And further, the tail gas collecting and absorbing device is further included and is connected with the powder grinding device, the conversion mill, the stirring reactor and the condensing device.
Furthermore, the device also comprises storage equipment, wherein the storage equipment comprises a powder material storage device connected with the crushing equipment and a concentrated solution or crystallized product storage device.
Further, the device comprises analytical instrument equipment, wherein the analytical instrument equipment is used for analyzing and detecting samples taken from a grinding device, a conversion mill, a stirring reactor, a concentration or crystallization device, a drying or heat treatment device and a storage device.
Further, the waste carbon residue crushing equipment comprises a jaw crusher, a cone crusher, a column crusher, a double-shaft crusher or an impact type fine crusher.
Furthermore, the milling equipment comprises a column mill, a Raymond mill, a vertical mill, a wind sweeping mill or a roller press, and matched powder selecting, screening and homogenizing equipment, so that the waste carbon residue powder with uniform composition and particles less than or equal to 200 mu m is obtained.
Further, the concentration and crystallization device is a multi-effect evaporation concentration or crystallization device, is used for concentrating or crystallizing a mixture solution obtained by solid-liquid separation, and relates to heat energy supply, heat exchange and condensation of an evaporation phase, recycling of condensed water, delivery of a concentrated solution or a crystallized substance and the like.
The tail gas collecting and absorbing equipment is used for collecting and absorbing tail gas generated in the processes of crushing, grinding, screening, homogenizing, conversion reaction, gel breaking, washing, concentrating, crystallizing and the like. The material component in the tail gas comprises H2O、NH3、CO2、H2、CH4、N2And trace amounts of dust; in which the gas phase H2Recycling O by condensation, NH3、CO2The dust is absorbed and utilized by an absorbent, and the combustible gas H2、CH4Collected for storage or entered into a combustion furnace for use as fuel.
The analytical instrument is used for material component detection, material conversion effect and content control detection, product quality detection and environmental protection emission standard monitoring in all links of the production process.
Further, the conversion mill is a modified airtight ball mill, and a mill body is provided with a grinding body inlet and outlet, a powder inlet, a liquid material inlet, a gas outlet, a slurry outlet, a cleaning emptying port, a gas sampling port and a slurry sampling port; the grinding body is one or more than two of corundum balls, zirconia balls, ceramic balls, steel balls, stainless steel balls and alloy balls.
The invention has the beneficial effects that:
(1) the invention has the characteristics of convenient control of the process, easy industrial stable production, low production cost, no three-waste pollution, no equipment corrosion and the like.
(2) The invention solves the problems and the defects of the existing wet treatment and fire treatment production process. Provides an advanced and systematic solution for the harmless and resource recycling of the aluminum electrolysis waste carbon residue.
Drawings
FIG. 1 is a schematic process flow diagram of the conversion process of the present invention.
Fig. 2 is a schematic structural diagram of a system employed in the present invention.
FIG. 3 is an X-ray diffraction pattern of the aluminum electrolysis waste carbon residue used in example 1.
FIG. 4 is an X-ray diffraction chart of a mixed powder material B obtained in example 1.
FIG. 5 is a thermogram of the mixed powder material B obtained in example 1.
FIG. 6 is an X-ray diffraction diagram of the soluble mixture A obtained in example 1.
Detailed Description
The following examples further illustrate the technical solutions of the present invention, but the present invention is not limited to the examples and is not intended to limit the scope of the present invention.
As shown in fig. 2, the system of the invention comprises a waste carbon residue crushing device 1, a grinding device 2, a conversion mill 3, a stirring reactor 4 and a solid-liquid separation device 5 which are connected in sequence, wherein the solid-liquid separation device 5 is directly connected with a concentration or crystallization device 7 and a drying or heat treatment device 6, and the drying or heat treatment device 6 is connected with a crushing device 8; still include condensing equipment 9, tail gas collection absorption apparatus 10 and storage equipment, condensing equipment 9 is connected with concentration or crystallization apparatus 7, and tail gas collection absorption apparatus 10 all is connected with milling equipment 2, conversion mill 3, stirring reactor 4, condensing equipment 9, and storage equipment includes the storage device 12 of the powder material storage device 11 and concentrate or crystallization product that is connected with crushing apparatus.
The device also comprises analytical instrument equipment which is used for analyzing and detecting samples taken from the milling equipment, the conversion mill, the stirring reactor, the concentration or crystallization equipment, the drying or heat treatment equipment and the storage equipment.
The waste cathode carbon block crushing equipment comprises a jaw crusher, a cone crusher, a column crusher, a double-shaft crusher or an impact type fine crusher.
The powder grinding equipment comprises a column mill, a Raymond mill, a vertical mill, a wind sweeping mill or a roller press and a homogenization device matched with the powder selecting and screening machine, so that the waste carbon slag powder with uniform composition and particles less than or equal to 200 mu m is obtained.
The concentrating or crystallizing equipment is a multi-effect evaporating concentrating or crystallizing device, is used for concentrating or crystallizing a separation liquid of a soluble mixture obtained by solid-liquid separation, and relates to heat energy supply, heat exchange and condensation of an evaporation phase, recycling of condensed water, delivery of a concentrated solution or a crystallized substance and the like.
The tail gas collecting and absorbing equipment is used for collecting and absorbing tail gas generated in the processes of crushing, grinding and homogenizing, conversion reaction, gel breaking and washing, concentration, crystallization and the like. The material component in the tail gas comprises H2O、NH3、CO2、H2、CH4、N2And trace amounts of dust; in which the gas phase H2Recycling O by condensation, NH3、CO2The dust is absorbed and utilized by an absorbent, and the combustible gas H2、CH4Collected for storage or entered into a combustion furnace for use as fuel.
The conversion mill is a modified airtight ball mill, and a mill body is provided with a grinding body inlet and outlet, a powder inlet, a liquid material inlet, a gas outlet, a slurry outlet, a cleaning emptying port, a gas sampling port and a slurry sampling port; the grinding body is one or more than two of corundum balls, zirconia balls, ceramic balls, steel balls, stainless steel balls and alloy balls.
Example 1
(1) Crushing the aluminum electrolysis waste carbon residue in a high-speed crusher, sieving by a 200-mesh sieve, and performing mechanochemical conversion on sodium-containing and fluorine-containing compounds by adopting undersize. Determining the mass content of sodium and fluorine elements in unit mass of the aluminum electrolysis waste carbon residue powder by adopting a chemical analysis method, and determining CN in unit mass of the aluminum electrolysis waste carbon residue powder by adopting the chemical analysis method-Mass content of ions.
(2) 200g of stainless steel ball is added into a conversion mill, 100g of waste carbon residue powder and 45g of CaSO are weighed4·2H2O、2.5g CaO、2g K2S2O8Adding into a conversion mill, mixing, and adding N2Displacing air from the inversion mill and adding 300g H to the inversion mill2And O. Starting the conversion mill, rotating speed of 100rpm, temperature of 25 ℃ and conversion reaction time of 2 h.
And transferring the slurry to a stirring reactor after the conversion reaction, wherein the stirring speed is 1000rpm, the temperature is 95 ℃, and the stirring reaction is carried out for 90min at constant temperature.
Respectively passing the tail gas generated in the step (1) and the step (2) through an absorber using water as an absorbent and an absorber using CaO as an absorbent, wherein the dust and the NH are3、CO2Is absorbed by H2、CH4And (4) carrying out combustion oxidation.
(3) Carrying out negative pressure suction filtration on the slurry after the stirring reaction, transferring a filter cake into a conversion mill after suction filtration, and adding 200gH2Dispersing, washing and then pumping filtration of O in a conversion mill, repeatedly washing and pumping filtration until the final filtrate uses 2mol/L BaCl2The solution was checked for precipitate and the filtrates were combined.
And (3) carrying out reduced pressure evaporation, concentration and crystallization on the filtrate, and drying for 10 hours in a vacuum drying oven at 100 ℃ to obtain a soluble mixture A.
(4) And drying the filter cake at 120 ℃ under normal pressure for 20h, and crushing the dried product to obtain a mixed powder material B of the fluorine-containing mineral substance and the carbon.
And (3) calcining the mixed powder material B in a high-temperature furnace at 900 ℃ for 3h in an air atmosphere, wherein the carbon component is completely oxidized and combusted, and the residue of the mixed powder material B is a mixture C of fluorine-containing mineral substances.
As can be seen from FIG. 3, the main phase components of the aluminum electrolysis waste carbon residue used in example 1 are C, NaF and Na3AlF6、AlF3、LiF、MgF2、CaF2、AlN。
As can be seen from FIG. 4, C, CaF was the main phase component of the mixed powder B of a fluorine-containing mineral and carbon obtained in example 12、MgF2、Al2O3、SiO2、CaO、CaSO4. Illustrating NaF and Na in the waste carbon residue3AlF6、AlF3The fluoride components such as LiF and the like are completely converted into mineral CaF2、MgF2。
As can be seen from the thermal analysis of the mixed powder material B in FIG. 5, the residue ratio at 900 ℃ was 43.8%, and the burnout ratio was 56.2%.
As can be seen from FIG. 6, the main component of the soluble mixture A obtained by the treatment of example 1 was Na2SO4、K2SO4、Li2SO4、MgSO4、Al2(SO4)3、Na2Si2O5、SiO2To explain NaF and Na in the waste carbon residue3AlF6、AlF3Fluoride components such as LiF have all been converted.
From these test analysis data it can be seen that: example 1 realizes the complete conversion of sodium-containing and fluorine-containing compounds in the aluminum electrolysis waste carbon residue, and thoroughly removes the harm of fluoride and cyanide in the aluminum electrolysis waste carbon residue.
Example 2
(1) Crushing the aluminum electrolysis waste carbon residue in a high-speed crusher, sieving by a 200-mesh sieve, and performing mechanochemical conversion on sodium-containing and fluorine-containing compounds by adopting undersize. Determining the mass content of sodium and fluorine elements in unit mass of the aluminum electrolysis waste carbon residue powder by adopting a chemical analysis method, and determining CN in unit mass of the aluminum electrolysis waste carbon residue powder by adopting the chemical analysis method-Mass content of ions.
(2) Adding 300g of stainless steel ball into a conversion mill, weighing 100g of waste carbon residue powder and 40g of MgSO40.8g of ethylene glycol and 3g of Na2S2O8Adding into a conversion mill, mixing, and adding N2Displacing air from the inversion mill and adding 400g H to the inversion mill2And O. Starting the conversion mill, wherein the rotating speed is 400rpm, the temperature is 35 ℃, and the conversion reaction time is 3 h.
And transferring the slurry to a stirring reactor after the conversion reaction, wherein the stirring speed is 800rpm, the temperature is 100 ℃, and the stirring reaction is stopped for 100min at constant temperature.
Respectively passing the tail gas generated in the step (1) and the step (2) through an absorber using water as an absorbentAnd an absorber using CaO as an absorbent, wherein dust and NH are contained3、CO2Is absorbed by H2、CH4And (4) carrying out combustion oxidation.
(3) Carrying out negative pressure suction filtration on the slurry after the stirring reaction, transferring a filter cake into a conversion mill after suction filtration, and adding 300gH2Dispersing, washing and then pumping filtration of O in a conversion mill, repeatedly washing and pumping filtration until the final filtrate uses 2mol/L BaCl2The solution was checked for precipitate and the filtrates were combined.
And (3) carrying out reduced pressure evaporation, concentration and crystallization on the filtrate, and drying for 10 hours in a vacuum drying oven at 100 ℃ to obtain a soluble mixture A.
(4) And drying the filter cake at 120 ℃ under normal pressure for 20h, and crushing the dried product to obtain a mixed powder material B of the fluorine-containing mineral substance and the carbon.
And (3) calcining the mixed powder material B in a high-temperature furnace at 1200 ℃ for 2h in an air atmosphere, wherein the carbon component is completely oxidized and combusted, and the residue of the mixed powder material B is a mixture C of fluorine-containing mineral substances.
Experimental results show that the example 2 realizes the complete conversion of sodium-containing and fluorine-containing compounds in the aluminum electrolysis waste carbon slag, and thoroughly removes the harm of fluoride and cyanide in the aluminum electrolysis waste carbon slag.
Example 3
(1) Crushing the aluminum electrolysis waste carbon residue in a high-speed crusher, sieving by a 200-mesh sieve, and performing mechanochemical conversion on sodium-containing and fluorine-containing compounds by adopting undersize. Determining the mass content of sodium and fluorine elements in unit mass of the aluminum electrolysis waste carbon residue powder by adopting a chemical analysis method, and determining CN in unit mass of the aluminum electrolysis waste carbon residue powder by adopting the chemical analysis method-Mass content of ions.
(2) Adding 400g of stainless steel ball into a conversion mill, weighing 100g of waste carbon residue powder and 30g of Ce2(SO4)3、2g(NH4)2S2O8Adding into a conversion mill, mixing, and adding N2Displacing air from the inversion mill and adding 350g H to the inversion mill2And O. The conversion mill is started, the rotating speed is 700rpm, the temperature is 50 ℃, and the conversion reaction time is 1.5 h.
And transferring the slurry to a stirring reactor after the conversion reaction, wherein the stirring speed is 500rpm, the temperature is 110 ℃, and the stirring reaction is carried out for 110min at constant temperature.
Respectively passing the tail gas generated in the step (1) and the step (2) through an absorber using water as an absorbent and an absorber using CaO as an absorbent, wherein the dust and the NH are3、CO2Is absorbed by H2、CH4And (4) carrying out combustion oxidation.
(3) Carrying out negative pressure suction filtration on the slurry after the stirring reaction, transferring a filter cake into a conversion mill after suction filtration, and adding 350gH2Dispersing, washing and then pumping filtration of O in a conversion mill, repeatedly washing and pumping filtration until the final filtrate uses 2mol/L BaCl2The solution was checked for precipitate and the filtrates were combined.
And (3) carrying out reduced pressure evaporation, concentration and crystallization on the filtrate, and drying for 10 hours in a vacuum drying oven at 100 ℃ to obtain a soluble mixture A.
(4) And drying the filter cake at 120 ℃ under normal pressure for 20h, and crushing the dried product to obtain a mixed powder material B of the fluorine-containing mineral substance and the carbon.
And (3) calcining the mixed powder material B in a high-temperature furnace at 1100 ℃ for 2h in an air atmosphere, wherein the carbon component is completely oxidized and combusted, and the residue of the mixed powder material B is a mixture C of fluorine-containing mineral substances.
Experimental results show that the example 3 realizes the complete conversion of sodium-containing and fluorine-containing compounds in the aluminum electrolysis waste carbon slag, and thoroughly removes the harm of fluoride and cyanide in the aluminum electrolysis waste carbon slag.

Claims (9)

1. A method for converting sodium-containing compounds and fluorine-containing compounds in aluminum electrolysis waste carbon residues is characterized by comprising the following steps:
(1) crushing, grinding and homogenizing the aluminum electrolysis waste carbon slag to obtain aluminum electrolysis waste carbon slag powder with particles less than or equal to 200 mu m; analyzing and determining the mole number or mass of sodium and the mole number or mass of fluorine in the unit mass of the aluminum electrolysis waste carbon residue powder; analysis and determination of CN in unit mass of aluminum electrolysis waste carbon residue powder-The number of moles or mass of ions;
grinding bodyAdding into a conversion mill, and then performing air evacuation or N on the conversion mill2Replacement, namely adding the measured aluminum electrolysis waste carbon residue powder into a conversion mill, controlling the mass ratio of the aluminum electrolysis waste carbon residue powder to a grinding body to be 1 (0.2-10), adding the measured water into the conversion mill, and controlling the solid-liquid mass ratio of the aluminum electrolysis waste carbon residue powder to the water to be 1 (1-10);
adding a conversion agent of a sodium-containing compound and a fluorine-containing compound into a conversion mill according to the amount which is 1-3 times of the stoichiometric ratio of the chemical reaction of converting the sodium-containing compound and the fluorine-containing compound into corresponding products in the aluminum electrolysis waste carbon residue powder or according to the amount which is 5-80% of the mass of the aluminum electrolysis waste carbon residue powder;
adding a grinding aid into a conversion mill according to the mass of 0-1% of the aluminum electrolysis waste carbon residue powder;
(2) after the step (1) is finished, starting the conversion mill, and controlling the rotation speed of the conversion mill to be 10-1000 rpm and the conversion temperature to be 10-110 ℃; in the conversion process, the slurry is sampled and analyzed and checked in batches at regular time until Na in the solid phase of the slurry+The ion content meets the enterprise standard and the soluble F-Stopping the conversion grinding when the ion content meets the national emission standard;
(3) after the step (2) is completed, transferring the slurry into a stirring reactor for gel breaking and aging treatment, controlling the temperature to be 60-150 ℃ and the treatment time to be 0.5-5 h;
(4) carrying out solid-liquid separation on the slurry obtained in the step (3) by adopting a filtering or centrifugal separation mode, putting the water-containing solid-phase substance into a conversion mill or a stirring reactor, taking water as a washing agent, repeating the dispersion washing and the solid-liquid separation for a plurality of times according to the solid-liquid mass ratio of 1 (1-10), washing until the content of soluble ions in the solid-phase substance meets the enterprise standard, combining the separation liquid, and respectively obtaining a mixture of wet fluorine-containing mineral substances and carbon, namely the water-containing solid-phase substance and a dilute solution of the mixture;
(5) drying or heat-treating the water-containing solid phase substance obtained in the step (4) at the temperature of 80-300 ℃ for 1-10 h, and then crushing to obtain a mixed powder material of the fluorine-containing mineral substance and carbon;
placing the mixed powder material containing the fluorine-containing mineral substances and carbon in an air atmosphere and a high-temperature furnace at the temperature of 700-1200 ℃ for calcining for 0.5-5 h, wherein the carbon component is completely oxidized and combusted, and the residue of the mixed powder material is a mixture containing the fluorine-containing mineral substances;
(6) concentrating or crystallizing the mixture dilute solution obtained in the step (4) to obtain a mixture concentrated solution or a solid phase mixture;
(7) according to CN in waste carbon slag powder for aluminum electrolysis-Conversion of ions to N2Or NH3And CO2The amount of the cyanide conversion agent is 1-5 times of the stoichiometric ratio of the chemical reaction, or the amount of the cyanide conversion agent is 0.1-10% of the mass of the waste carbon residue powder of the aluminum electrolysis, and the cyanide conversion agent is added into the step (2), the step (3) or the step (6) to oxidize and convert the cyanide-containing compound into harmless N2Or NH3And CO2The analysis and check are carried out on the transformation system in batches and at regular time until CN in the system-The conversion reaction is stopped when the ion content meets the national emission standard;
(8) the NH generated in the step (2) or the step (3) or the step (6)3、CO2、H2And (4) carrying out absorption conversion and drying on the O gas, and collecting the generated reducing gas or directly oxidizing and burning the reducing gas.
2. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon residue according to claim 1, wherein in all the steps, the pH is controlled to be not less than 6, no protonic acid substance is used, and the conversion agent of sodium-containing compounds and fluorine-containing compounds, the cyanide conversion agent and the grinding aid substance are used without chlorine elements.
3. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon slag according to claim 1, wherein the aluminum electrolysis waste carbon slag powder comprises two or more of C, Na, F, Al, Ca, O, N, Li, Mg, Si, K and Fe as main elements; the sodium-containing compound comprises NaF and Na3AlF6、NaCN、Na4[Fe(CN)6]Two or more of (1); the fluorine-containing compound comprises NaF and Na3AlF6、AlF3、LiF、CaF2、MgF2And KF.
4. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon residue according to claim 1, wherein the converting agent for the sodium-containing compounds and the fluorine-containing compounds comprises one or more than two of oxides, hydroxides, sulfates, nitrates, carbonates, acetates or citrates corresponding to each element of Ca, Al, Mg, Sr, Ba, La or Ce.
5. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon residue as claimed in claim 1, wherein the cyanide conversion agent comprises Na2CO3·1.5H2O2、K2CO3·1.5H2O2、Na2O2、K2O2、CaO2、SrO2、BaO2、H2O2、(NH4)2S2O8、Na2S2O8、K2S2O8、KMnO4、O2、O3One or more than two of them.
6. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon residue according to claim 1, wherein the grinding aid comprises one or more of polymeric polyol, polymeric alcohol amine, triisopropanolamine, ethylene glycol, propylene glycol, glycerol, diethylene glycol, triethanolamine, amide, stearic acid, oleic acid, sodium hexametaphosphate and sodium stearate.
7. The method for converting sodium-containing compounds and fluorine-containing compounds in the aluminum electrolysis waste carbon residue according to claim 1, wherein the conversion agent of sodium-containing compounds and fluorine-containing compounds, the cyanide conversion agent and the grinding aid are added in a solid, aqueous solution or gas state, and the method of adding the sodium-containing compounds, the cyanide conversion agent and the grinding aid at one time or in batches or continuously is adopted.
8. A conversion system for sodium-containing compounds and fluorine-containing compounds in aluminum electrolysis waste carbon residues is characterized by comprising waste carbon residue crushing equipment, grinding equipment, a conversion mill, a stirring reactor and solid-liquid separation equipment which are sequentially connected, wherein the solid-liquid separation equipment is directly connected with concentration or crystallization equipment and drying or heat treatment equipment, and the drying or heat treatment equipment is connected with the crushing equipment;
still include condensing equipment, tail gas collection absorption equipment, storage equipment and analytical instrument equipment, condensing equipment is connected with concentrated or crystallization equipment, tail gas collection absorption equipment and milling equipment, the conversion grinds, stirring reactor, condensing equipment all is connected, storage equipment includes the storage device of the powder material storage device and concentrate or the crystallization product that are connected with crushing apparatus, analytical instrument equipment is to getting from milling equipment, the conversion grinds, stirring reactor, concentrated or crystallization equipment, drying or heat treatment equipment, the sample of storage equipment carries out the analysis and detection.
9. The system for converting sodium-containing compounds and fluorine-containing compounds in aluminum electrolysis waste carbon slag according to claim 8, wherein the waste carbon slag crushing equipment comprises a jaw crusher, a cone crusher, a column crusher, a double-shaft crusher or an impact type fine crusher; the powder grinding equipment comprises a column mill, a Raymond mill, a vertical mill, an air swept mill or a roller press and powder selecting and screening homogenization equipment matched with the air swept mill or the roller press; the concentration or crystallization equipment is a multi-effect evaporation concentration or crystallization device; the conversion mill is a modified airtight ball mill, and a mill body is provided with a grinding body inlet and outlet, a powder inlet, a liquid material inlet, a gas outlet, a slurry outlet, a cleaning emptying port, a gas sampling port and a slurry sampling port; the grinding body is one or more than two of corundum balls, zirconia balls, ceramic balls, steel balls and alloy balls.
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