CA1168420A - Method for processing nephelite to alumina - Google Patents
Method for processing nephelite to aluminaInfo
- Publication number
- CA1168420A CA1168420A CA000364768A CA364768A CA1168420A CA 1168420 A CA1168420 A CA 1168420A CA 000364768 A CA000364768 A CA 000364768A CA 364768 A CA364768 A CA 364768A CA 1168420 A CA1168420 A CA 1168420A
- Authority
- CA
- Canada
- Prior art keywords
- blend
- sintering
- nephelite
- alumina
- heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Processing Of Solid Wastes (AREA)
- Treatment Of Sludge (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Disclosed is a method for processing nephelite to alumina, comprising the steps of blend preparation, blend sintering, and hydrochemical treatment of the resultant sinter cake, and characterised in that milling of the feedstock ma-terials in the blend preparation step is combined with simul-taneously drying them by the use of exhaust gases from the blend sintering stage while in the blend sintering step heating of the blend to 900 to 950°C is effected within 1 to 3 minutes with the blend in a fluidized state and the desiliconization and causticization slurries resulting from the hydrochemical treat-ment step are recycled to the blend sintering stage. The method may be used for producing alumina from nephelite having an alum-ina content of 20 to 30% by weight.
Disclosed is a method for processing nephelite to alumina, comprising the steps of blend preparation, blend sintering, and hydrochemical treatment of the resultant sinter cake, and characterised in that milling of the feedstock ma-terials in the blend preparation step is combined with simul-taneously drying them by the use of exhaust gases from the blend sintering stage while in the blend sintering step heating of the blend to 900 to 950°C is effected within 1 to 3 minutes with the blend in a fluidized state and the desiliconization and causticization slurries resulting from the hydrochemical treat-ment step are recycled to the blend sintering stage. The method may be used for producing alumina from nephelite having an alum-ina content of 20 to 30% by weight.
Description
~6~
The pXesent inYention xelates to the field of non-ferrous metalluxg~ and, more particularly, to a method ~o~ p~o-cessing nephelite to alum~naO
The method may be utilized ~or producing alumina from nephelite containing alu~ina in an amount of between 20 and 30%
by weight.
In the present world practice, alumina is generally obtained from bauxites which ha~e a high alumina content,`but bauxite resources tend to be depleting, with bauxite prices increasing accordingly. In such a situation, raw materials low in alumina, nephelite specifically, become of practical interest for commercial production of alu~ina.
In the Soviet UniOn~ a multi-purpose processing method has been developed and commercialized for processing nephelite to alumina, cement, soda and potash. In this method, alumina is obtained by preparlng a blend, sintering it, and by subsequent hydrochemical treatement of the resultant sinter cake. The blend is composed of nephelite and limestone and contains about 30%
by weight of water. Sintering is carried out as a one-stage operation, in a layer cascading in a rotary kiln where the blend is heated from 50aC to 1250-1300C. Desiliconization and causticization slurries as waste products resulting from the hydrochemical treatment of siner cake are recycled to the blend preparation stage. (Ref. to: A.I. Lainer, N.I. Eremin, Ju.A.
Lainer, I.Z. Pevzner. ProizYodstvo glinozema (Production of alumina) Mo$co~, 19781.
Characteristics of th.is prior art method are high heat consu~ption rate$ due t~ t~e need ~or eyaporatin~ water ~ro.m the blend and raising the tempe~ature of the water vapor to that of 3Q the gases-exhausted from the kiln, said rate$ aye~aging about 1725 k~ per k~logramme o~ sinter cake, Apart from that, the blend layer cascading in th.e rotary kiln has an insufficient heat exchange suxface with the gas flow and a xather low heat-exchange coefficient. ~s a xesult drying and heating the blend to 900-95QRC, a sta~e accompanied by decarbonization, is a rather low-ef~iciency operation, the time re~uired for drying and heating to sald temperature being as long as 2 to 3 hours The invention is based on the objective of reducing the fuel consumption for blend sintering by eliminating water from the blend composition and raising the efficiency of the blend sintering step by effecting the heating and decarboniza-ing stage with the blend in a fluidized state.
To achieve this objective, there is provided a methodof processing nephelite to alumina, comprising the steps of blending, blend sintering, and hydrochemical treatment of the resultant sinter cake, wherein, according to the present inven-tion, milling of the feedstock materials in the blend preparation step is combined with simultanteously drying them by the ex-haust gases from the blend sintering stage, while in the blend sintering step heating of the blend to 900 to 950C is effected within 1 to 3 minutes with the blend in a fluidized state and the desiliconization and causticization slurries resulting from the hydrochemical treatment step are recycled to the blend sintering stage.
In the method, milling of the stockfeed materials is combined with simultaneous drying of the feedstock by exhaust gases from the blend sintering stage, the heat consumption rates for evaporating water fxom the feedstock material and heating the water vapour tQ the exhaus gas temperature ayerag-ing ~5Q kJ per kilogramme of sinter cake, which is 1475 kJ/kg ~nte~ cake less than the hea~t consumption for water evaporation 3Q from the blend a~d water yapor heating to the kiln exhaust gas temperature involved in the pxioX art method.
Blend sinterlng is carried out in two heat-treating ;/l ~ - 2 ~
stages. Heating tQ 90Q~9SQQC, accompanied by decarbonization;
is e~fected with the blend In a ~luidized stateand thus having a large heat exchan~e surface and a high heat-exchange coefficient, the heating time being therefore as short as 1 to 3 minutes.
Further heating to 125Q-130QC is effected with the blend spread in a layer cascading in a rotary kiln. Characteristic of this latter heating stage are enhanced rates of sinter cake formation reactions, this being due to the fact that owing to the rapid heating of the blend at the previous stage there is not sufficient time for the newly fo~med active compounds to lose their reactiv-ity. Accelerated sinter cake formation coupled with the insig-nificant heat consumption by the blend combine to increase the specific efficiency of this stage in the sintering process by about 4 times.
The waste products from the hydrochemical treatment of the sinter cake, in the form of desiliconization and causti-cization slurries, are recycled to the sintering stage, and this dispenses with the problem of wastes by utilizing them within the alumina production setup itself.
The lower temperature limit for heating the blend in a fluidized state is predetermined by the fact that at 900C
the pressure of carbon dioxide released due tolimestone de-carbonization equals atmospheric pressure, enabling the reaction to proceed at sufficient speed. When the blend temeprature exceeds 95QC, the blend becomes soft and sticky, adhering to the walls of the e~ipment and interfe~ing with the proper operation thereof. Decreas~ng the time fo~ heating the blend in a fluidiz-ed state to ~00-95~QC to below 1 minute will not permit the desired degree of decarbonizat~on af the blend ~this is close 3Q to lOQ~l, while incxea;s~n~ the~heating time to above 3 minutes will seXve no useful Rurpa~se since the process efficinecy will be reduced while the degxee of blend decarbonization will remain ~6~æll~
unchanged, Varyin~ the temperature conditions and duration of the indivi~dual s~tages in the sintering process within the limits specified serves the purpose of achieving identical results by compensating for possible variations in the composition of feedstock materials or in the design features of sintering equipment.
The method for processing nephelite to alumina is implemented as follows.
Limestone is crushed to a lump size of 200 to 250 mm and then pre-milled in, for example, a self-attrition (Aero-fall type) mill, while being pre-dried by exhaust gases from the sintering stage to a residual moisture content of 1% by weight. Next, pre-dried limestone grit is combined with dry powdered nephelite for milling together in, for example, a tubular ball mill. Ratio adjustment of blend components is carried out continuously by varying the component flow rates.
A mixing vessel equipped with an air stirring capability is further used to homogenize the blend. The blend thus prepared is sent to a sintering plant comprising cyclone typ heat exchangers, a decarbonizer, a rotary kiln, and a cooler. The cyclone type heat exchangers and decarbonizer serve to heat the finely ground dry blend in a fluidized state to 900-950C while ; decarbonizing it in the process, the heating time being 1 to 3 minutes. Then the rotary kiln takes over, heating the blend in a cacading layer from 90Q-950C to 1250-1300~C. The heating time being 25 to 35 minutes. Each heating stage has an inde-pendent heat generator connected to a sinter cake coaler fox the suppl~ of fuel combust~on air~ The exhau t gas from the sinter~ng stage are util~zed for d~ying the limestone being ground ~n the self-attr~tion mill. Dust is recovered from the spent gases afterwards and recycled to the sintering stage.
, j ~
~6~2~ , To obtain alumina, the sinter cake passed through the co~ler is subjected to h~dxochemical treatment. The waste products of the hydrochemical treatment are utilized as raw materials for the producti~on of cement, soda and potash, with the ex-ception of desiliconization and c~usticization slurries which are recycled to the sintering stage along with the dust re-covered from the sintering-stage exhaust gases.
Compared to the prior art practice, the method for processing nephelite to alumina offers the follow-ing advantages:
fuel consumption for blend sintering can be re-duced, in terms of comparison fuel (calorific value 7000 kcal/
kg or 29350 kJ/kg), by 0.425 t per tonne of alumina (with 8 t of sinter cake used to produce 1 t of alumina), which is of primary importance in a situation of energy crisis;
- specific sintering process efficinecy can be in-creased by 4 times, and so can be the kiln unit capacity, up to 500 t/h; this will eut down the capital investments, make for faster return and payoff, and also enhance labour produeti-vity;
- the sintering proeess ean be fully automated for greater proeess stability and higher sinter eake quality.
The following speeifie examples of embodiment of the ne~helite-to-alumina proeessing method will af-ford a better understanding of the present invention.
Example Lime$tone with an initial moi~tuxe eontent of 16%
by weight~ta~ken in an amount Rf 987 kg per tonne of sintex eake, I;
wa~ cru$hed to a lump $ize of 20a to 250 mm and then ground in a self-attx~ n miL1 to a gXit eontaining 5Q% by weight partieles sized Ot 08 mm plus, while being simultaneousl~
dried by exhaust gases from the sintering stage to a resi-i~f dual moisture content of l~ by weight. Dr~v limestone grit combined w~th nephelite having a 65% content of 0.1 to 1.0 mm particles and a moisture content of 0.4% b~v weight and taken in an amount of 528 kg per tanne of sinter cake, were ground to-gether in a tubular ball mill. Adjustment of the limestone-to-nephelite ratio was e~fected continuously by varying their respective flows to the mill. The resulting blend was further homogenized in a mixing vessel equipped with an air stirring capability. The properly adjusted and homogenized finished blend was heated for 2 minutes in a fluidized state to 925C in a system comprising severa] heat exchangers arranged in series and a decarbonizer, with the blend being decarbonized to the extent of 90%. Further heating of the blend to 1275~C, for another 30 minutes, was effected in a rotary kiln, in a cascading layer. From the rotary kiln the sinter cake was sent to a cooler. Heat consumption for sintering was 2930 kJ
per kilogramme of sinter cake. Air required for fuel combus-tion was derived from the sinter cake cooler. The cooled sinter cake was subjected to hydrochemical treatment. The slurries formed as waste products of the hydrochemical treat-ment, i.e. resulting from desiliconization of the aluminate solution and causticization of the carbonate solution, in the amounts of 50 and 25 kg per kilogramme of sinter cake, respec-tively, were recycled to the sintering stage, specifically to the rotary kiln. Recovery of the useful components from the sinter cake w-as as follows: ~12Q3, 88~ by weight; (Na2O ~ K2~, 92.5~ by weight~
Example 2 Blend prepar~tion~ blend s~ntering and hydrochemical t~eatment of the resultant sinter cake were carried out es-sentlally as descxibed in Example 1 except that the heating temp-erature and time at the fluidized heating stage were 900qC and s ,:
6~
3 minutes,, ~espectively. The degree of decaronbization ~f the blend wa~s 9.0%. Recover~ of,the useful component f~om the sinter cake was: A12O3; 88% by weight; (Na2O ~K2O),, 92.5% by weight.
Example 3 Blend preparation, blend sintering and hydrochemicai treatment of the resultant sinter cake were carried out essen-tially as described in Example 1 except that the heating temperat.ure and time at the fluidized heating stage were 950C
and 1 minute, respectively. The degree of decarbonization of of the blend was 90%. Recovery of the useful components from the sinter cake was: A12O3, 88% by~eight; (Na2O + K2O), 92.5%
by weight.
, .
The pXesent inYention xelates to the field of non-ferrous metalluxg~ and, more particularly, to a method ~o~ p~o-cessing nephelite to alum~naO
The method may be utilized ~or producing alumina from nephelite containing alu~ina in an amount of between 20 and 30%
by weight.
In the present world practice, alumina is generally obtained from bauxites which ha~e a high alumina content,`but bauxite resources tend to be depleting, with bauxite prices increasing accordingly. In such a situation, raw materials low in alumina, nephelite specifically, become of practical interest for commercial production of alu~ina.
In the Soviet UniOn~ a multi-purpose processing method has been developed and commercialized for processing nephelite to alumina, cement, soda and potash. In this method, alumina is obtained by preparlng a blend, sintering it, and by subsequent hydrochemical treatement of the resultant sinter cake. The blend is composed of nephelite and limestone and contains about 30%
by weight of water. Sintering is carried out as a one-stage operation, in a layer cascading in a rotary kiln where the blend is heated from 50aC to 1250-1300C. Desiliconization and causticization slurries as waste products resulting from the hydrochemical treatment of siner cake are recycled to the blend preparation stage. (Ref. to: A.I. Lainer, N.I. Eremin, Ju.A.
Lainer, I.Z. Pevzner. ProizYodstvo glinozema (Production of alumina) Mo$co~, 19781.
Characteristics of th.is prior art method are high heat consu~ption rate$ due t~ t~e need ~or eyaporatin~ water ~ro.m the blend and raising the tempe~ature of the water vapor to that of 3Q the gases-exhausted from the kiln, said rate$ aye~aging about 1725 k~ per k~logramme o~ sinter cake, Apart from that, the blend layer cascading in th.e rotary kiln has an insufficient heat exchange suxface with the gas flow and a xather low heat-exchange coefficient. ~s a xesult drying and heating the blend to 900-95QRC, a sta~e accompanied by decarbonization, is a rather low-ef~iciency operation, the time re~uired for drying and heating to sald temperature being as long as 2 to 3 hours The invention is based on the objective of reducing the fuel consumption for blend sintering by eliminating water from the blend composition and raising the efficiency of the blend sintering step by effecting the heating and decarboniza-ing stage with the blend in a fluidized state.
To achieve this objective, there is provided a methodof processing nephelite to alumina, comprising the steps of blending, blend sintering, and hydrochemical treatment of the resultant sinter cake, wherein, according to the present inven-tion, milling of the feedstock materials in the blend preparation step is combined with simultanteously drying them by the ex-haust gases from the blend sintering stage, while in the blend sintering step heating of the blend to 900 to 950C is effected within 1 to 3 minutes with the blend in a fluidized state and the desiliconization and causticization slurries resulting from the hydrochemical treatment step are recycled to the blend sintering stage.
In the method, milling of the stockfeed materials is combined with simultaneous drying of the feedstock by exhaust gases from the blend sintering stage, the heat consumption rates for evaporating water fxom the feedstock material and heating the water vapour tQ the exhaus gas temperature ayerag-ing ~5Q kJ per kilogramme of sinter cake, which is 1475 kJ/kg ~nte~ cake less than the hea~t consumption for water evaporation 3Q from the blend a~d water yapor heating to the kiln exhaust gas temperature involved in the pxioX art method.
Blend sinterlng is carried out in two heat-treating ;/l ~ - 2 ~
stages. Heating tQ 90Q~9SQQC, accompanied by decarbonization;
is e~fected with the blend In a ~luidized stateand thus having a large heat exchan~e surface and a high heat-exchange coefficient, the heating time being therefore as short as 1 to 3 minutes.
Further heating to 125Q-130QC is effected with the blend spread in a layer cascading in a rotary kiln. Characteristic of this latter heating stage are enhanced rates of sinter cake formation reactions, this being due to the fact that owing to the rapid heating of the blend at the previous stage there is not sufficient time for the newly fo~med active compounds to lose their reactiv-ity. Accelerated sinter cake formation coupled with the insig-nificant heat consumption by the blend combine to increase the specific efficiency of this stage in the sintering process by about 4 times.
The waste products from the hydrochemical treatment of the sinter cake, in the form of desiliconization and causti-cization slurries, are recycled to the sintering stage, and this dispenses with the problem of wastes by utilizing them within the alumina production setup itself.
The lower temperature limit for heating the blend in a fluidized state is predetermined by the fact that at 900C
the pressure of carbon dioxide released due tolimestone de-carbonization equals atmospheric pressure, enabling the reaction to proceed at sufficient speed. When the blend temeprature exceeds 95QC, the blend becomes soft and sticky, adhering to the walls of the e~ipment and interfe~ing with the proper operation thereof. Decreas~ng the time fo~ heating the blend in a fluidiz-ed state to ~00-95~QC to below 1 minute will not permit the desired degree of decarbonizat~on af the blend ~this is close 3Q to lOQ~l, while incxea;s~n~ the~heating time to above 3 minutes will seXve no useful Rurpa~se since the process efficinecy will be reduced while the degxee of blend decarbonization will remain ~6~æll~
unchanged, Varyin~ the temperature conditions and duration of the indivi~dual s~tages in the sintering process within the limits specified serves the purpose of achieving identical results by compensating for possible variations in the composition of feedstock materials or in the design features of sintering equipment.
The method for processing nephelite to alumina is implemented as follows.
Limestone is crushed to a lump size of 200 to 250 mm and then pre-milled in, for example, a self-attrition (Aero-fall type) mill, while being pre-dried by exhaust gases from the sintering stage to a residual moisture content of 1% by weight. Next, pre-dried limestone grit is combined with dry powdered nephelite for milling together in, for example, a tubular ball mill. Ratio adjustment of blend components is carried out continuously by varying the component flow rates.
A mixing vessel equipped with an air stirring capability is further used to homogenize the blend. The blend thus prepared is sent to a sintering plant comprising cyclone typ heat exchangers, a decarbonizer, a rotary kiln, and a cooler. The cyclone type heat exchangers and decarbonizer serve to heat the finely ground dry blend in a fluidized state to 900-950C while ; decarbonizing it in the process, the heating time being 1 to 3 minutes. Then the rotary kiln takes over, heating the blend in a cacading layer from 90Q-950C to 1250-1300~C. The heating time being 25 to 35 minutes. Each heating stage has an inde-pendent heat generator connected to a sinter cake coaler fox the suppl~ of fuel combust~on air~ The exhau t gas from the sinter~ng stage are util~zed for d~ying the limestone being ground ~n the self-attr~tion mill. Dust is recovered from the spent gases afterwards and recycled to the sintering stage.
, j ~
~6~2~ , To obtain alumina, the sinter cake passed through the co~ler is subjected to h~dxochemical treatment. The waste products of the hydrochemical treatment are utilized as raw materials for the producti~on of cement, soda and potash, with the ex-ception of desiliconization and c~usticization slurries which are recycled to the sintering stage along with the dust re-covered from the sintering-stage exhaust gases.
Compared to the prior art practice, the method for processing nephelite to alumina offers the follow-ing advantages:
fuel consumption for blend sintering can be re-duced, in terms of comparison fuel (calorific value 7000 kcal/
kg or 29350 kJ/kg), by 0.425 t per tonne of alumina (with 8 t of sinter cake used to produce 1 t of alumina), which is of primary importance in a situation of energy crisis;
- specific sintering process efficinecy can be in-creased by 4 times, and so can be the kiln unit capacity, up to 500 t/h; this will eut down the capital investments, make for faster return and payoff, and also enhance labour produeti-vity;
- the sintering proeess ean be fully automated for greater proeess stability and higher sinter eake quality.
The following speeifie examples of embodiment of the ne~helite-to-alumina proeessing method will af-ford a better understanding of the present invention.
Example Lime$tone with an initial moi~tuxe eontent of 16%
by weight~ta~ken in an amount Rf 987 kg per tonne of sintex eake, I;
wa~ cru$hed to a lump $ize of 20a to 250 mm and then ground in a self-attx~ n miL1 to a gXit eontaining 5Q% by weight partieles sized Ot 08 mm plus, while being simultaneousl~
dried by exhaust gases from the sintering stage to a resi-i~f dual moisture content of l~ by weight. Dr~v limestone grit combined w~th nephelite having a 65% content of 0.1 to 1.0 mm particles and a moisture content of 0.4% b~v weight and taken in an amount of 528 kg per tanne of sinter cake, were ground to-gether in a tubular ball mill. Adjustment of the limestone-to-nephelite ratio was e~fected continuously by varying their respective flows to the mill. The resulting blend was further homogenized in a mixing vessel equipped with an air stirring capability. The properly adjusted and homogenized finished blend was heated for 2 minutes in a fluidized state to 925C in a system comprising severa] heat exchangers arranged in series and a decarbonizer, with the blend being decarbonized to the extent of 90%. Further heating of the blend to 1275~C, for another 30 minutes, was effected in a rotary kiln, in a cascading layer. From the rotary kiln the sinter cake was sent to a cooler. Heat consumption for sintering was 2930 kJ
per kilogramme of sinter cake. Air required for fuel combus-tion was derived from the sinter cake cooler. The cooled sinter cake was subjected to hydrochemical treatment. The slurries formed as waste products of the hydrochemical treat-ment, i.e. resulting from desiliconization of the aluminate solution and causticization of the carbonate solution, in the amounts of 50 and 25 kg per kilogramme of sinter cake, respec-tively, were recycled to the sintering stage, specifically to the rotary kiln. Recovery of the useful components from the sinter cake w-as as follows: ~12Q3, 88~ by weight; (Na2O ~ K2~, 92.5~ by weight~
Example 2 Blend prepar~tion~ blend s~ntering and hydrochemical t~eatment of the resultant sinter cake were carried out es-sentlally as descxibed in Example 1 except that the heating temp-erature and time at the fluidized heating stage were 900qC and s ,:
6~
3 minutes,, ~espectively. The degree of decaronbization ~f the blend wa~s 9.0%. Recover~ of,the useful component f~om the sinter cake was: A12O3; 88% by weight; (Na2O ~K2O),, 92.5% by weight.
Example 3 Blend preparation, blend sintering and hydrochemicai treatment of the resultant sinter cake were carried out essen-tially as described in Example 1 except that the heating temperat.ure and time at the fluidized heating stage were 950C
and 1 minute, respectively. The degree of decarbonization of of the blend was 90%. Recovery of the useful components from the sinter cake was: A12O3, 88% by~eight; (Na2O + K2O), 92.5%
by weight.
, .
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for processing nephelite to alumina, comprising the steps of blend preparation of nephelite with limestone, blend sintering, and hydrochemical treatment of the resultant sinter cake, which milling of the feedstock materials in the blend preparation step is combined with simultaneously drying the feedstock materials using exhaust gases from the blend sintering step while in the blend sintering step heating of the blend to 900 to 950°C is effected within 1 to 3 minutes with the blend in a fluidized state and the desiliconization and causticization slurries resulting from the hydrochemical treatment step are recycled to the blend sintering step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SU2836902 | 1979-11-15 | ||
| SU2836902 | 1979-11-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1168420A true CA1168420A (en) | 1984-06-05 |
Family
ID=20858039
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000364768A Expired CA1168420A (en) | 1979-11-15 | 1980-11-14 | Method for processing nephelite to alumina |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5696725A (en) |
| CA (1) | CA1168420A (en) |
| DE (1) | DE3042862C2 (en) |
| DK (1) | DK149528C (en) |
| IT (1) | IT1209279B (en) |
| MX (1) | MX154362A (en) |
| NO (1) | NO155767C (en) |
| PT (1) | PT72054B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102502737A (en) * | 2011-11-03 | 2012-06-20 | 沈阳铝镁设计研究院有限公司 | Method for dissolving out alumina clinker |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2633318C3 (en) * | 1976-07-23 | 1982-05-13 | Vsesojuznyj naučno-issledovatel'skij i proektnyj institut aljuminievoj, magnievoj i elektrodnoj promyšlennosti, Leningrad | Process for the recovery of alumina from the mineral, aluminum, silicon and iron oxides containing portion of solid fuels |
-
1980
- 1980-09-14 MX MX184777A patent/MX154362A/en unknown
- 1980-11-12 NO NO803402A patent/NO155767C/en unknown
- 1980-11-13 PT PT72054A patent/PT72054B/en unknown
- 1980-11-13 DE DE3042862A patent/DE3042862C2/en not_active Expired
- 1980-11-14 CA CA000364768A patent/CA1168420A/en not_active Expired
- 1980-11-14 JP JP16063380A patent/JPS5696725A/en active Pending
- 1980-11-14 DK DK486580A patent/DK149528C/en not_active IP Right Cessation
- 1980-11-17 IT IT8026034A patent/IT1209279B/en active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102502737A (en) * | 2011-11-03 | 2012-06-20 | 沈阳铝镁设计研究院有限公司 | Method for dissolving out alumina clinker |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8026034A0 (en) | 1980-11-17 |
| IT1209279B (en) | 1989-07-16 |
| DK486580A (en) | 1981-05-16 |
| DK149528B (en) | 1986-07-14 |
| NO803402L (en) | 1981-05-18 |
| NO155767B (en) | 1987-02-16 |
| DE3042862C2 (en) | 1983-11-17 |
| DK149528C (en) | 1987-01-12 |
| PT72054A (en) | 1980-12-01 |
| PT72054B (en) | 1981-09-24 |
| MX154362A (en) | 1987-07-29 |
| NO155767C (en) | 1987-05-27 |
| DE3042862A1 (en) | 1981-05-27 |
| JPS5696725A (en) | 1981-08-05 |
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