Red soil nickel ore in rotary kiln directly the reduction grain nickel iron method
Technical field:
The invention belongs to the Non-ferrous Metallurgy field, particularly a kind of red soil nickel ore directly reduces the method for grain nickel iron.
Background technology:
Development along with society, the progress of science and technology, stainless steel is used widely in the world, and traditional nickel master metal will be extracted from nickel sulfide ore, but its resource can not satisfy needs of society, forces people to extracting metallic nickel in the red soil nickel ore that takes up an area of ball nickel resources about 80%.
The technology of extracting metallic nickel in the present red soil nickel ore in the world has three kinds.That is: thermal process, wet processing, fiery wet method combined process.Wherein thermal process is mainly blast furnace and rotary kiln-electrosmelting.The outer reducing and smelting ferronickel technology of stove not only requires the grade of red soil nickel ore to want high, and needs to consume a large amount of energy, and the silicon magnesium ratio of raw material is also had requirement.Wet processing, it is the sulfuric acid pressure leaching process, though realized suitability for industrialized production at present, but because it adopts condition of high voltage operation, equipment, scale, investment, operation control and ore grade, magnesium oxide etc. there is higher requirement, especially in sulfuric acid expensive today, extract metallic nickel with pickling process, cost height not only, and produce a large amount of waste liquids, can cause severe contamination to environment.Fire wet method combined process mainly is raw ore reducing roasting-ammonia soaking technology, handle low-grade red soil nickel ore, but the rate of recovery is low, cost is high, has belonged to superseded technology.Above-mentioned processing unit is not only invested greatly, energy consumption is many, and its ferronickel grade of producing is also lower.At present domestic have some areas to utilize the blast-furnace smelting Rhometal, and same the existence invested the shortcoming big, that tooling cost is high, and seriously polluted environment.
In first to file (patent publication No.: the process for preparing nickel ferroalloy by melting and reducing laterite nickel ore of Central South University's invention 200710034750.0), at first nickel oxide in the red soil nickel ore and rhombohedral iron ore prereduction are converted into metallic nickel and metallic iron or Z 250, utilize wet magnetic separation then, make ferronickel significantly enrichment the time, harmful elements such as gangue and sulphur, phosphorus are removed, and the ferronickel concentrate that at last prereduction is obtained carries out melting and reducing and prepares Rhometal.Smelting reduction process production that its production stage is: prereduction---magnetic separation---, its technology is complicated, tooling cost is higher, the energy consumption height of smelting ferronickel alloy, and the nickel grade of producing is not high, and economic benefit is lower, before particularly red soil nickel ore is gone into the rotary kiln reduction, meal must dry grinding, pressure ball oven dry again, and investment goods is big.
At first to file (number of patent application: the reduction of the dissimilar red soil nickel ores of Kunming Institute of Precious Metals's invention 200610163831.6)---mill treatment process, its production stage is: with the broken mill of red soil nickel ore, add carbonaceous raw material, composite additive mix grinding, become pelletizing with ball egg shaping mechanism, dry then, after adopting the rotary kiln reducing roasting, carry out slightly broken, after carrying out wet ball grinding then, adopt shaking table to carry out gravity treatment, the ferronickel concentrate that gravity treatment obtains adopts 3000-5000 Gauss's magnetic separator to sort, and just obtains high-grade ferronickel collective concentrate.Though the nickel grade is higher in the ferronickel concentrate that this method is selected, not the grain nickel iron alloy, its complete processing is complicated, cost is higher, can not directly advance the electrosmelting stainless steel.The red soil nickel ore reduction still needs drying, and grinding accounts for 90% to 120 orders, reproduces the ball oven dry, and facility investment is still very big.
Foregoing invention all has different creativity and innovation characteristics, before but red soil nickel ore is gone into rotary kiln, the complete processing complexity, need fragmentation earlier, mix grinding, system pelletizing, just send in the rotary kiln after drying is handled and reduce, its equipment is complicated, production cost is higher, the pelletizing of especially neutralizing, breeze and the coal ash that falls friction formation that constantly roll in kiln is being subjected under the oxygenizement of furnace gas, makes the red soil nickel ore powder generation (FeO) of partial reduction and the (SiO in the coal ash
2) form low-melting ferric metasilicate, produce the sticking kiln of high viscosity liquid phase, form the long thick ring formation of kliner coating, influence ordinary production.In addition, that uses in the foregoing invention receives salt additives, easily is reduced to be the steam effusion bed of material under the rotary kiln reductive condition, to cold zone condensation deposition, forms the sticking kiln of low melting point silicate with kiln lining, forms the long thick ring formation of kliner coating.Moreover foregoing invention, red soil nickel ore is reducing roasting in rotary kiln, through grinding, what magneticly elect is ferronickel fine ore rather than grain nickel iron alloy, can not directly enter the electrosmelting stainless steel, also needs could smelt into Rhometal molten the branch through smelting furnace.
Summary of the invention:
The method that the purpose of this invention is to provide a kind of red soil nickel ore direct reduction grain nickel iron in rotary kiln, it has remedied red soil nickel ore reduction in rotary kiln at present, cooling, ball milling, the technologic defective of magnetic separation ferronickel fine ore, can obtain nickeliferous Rhometal particle of high grade, replace smelting furnace smelting ferronickel alloy technology.
The present invention is a kind of red soil nickel ore is produced grain nickel iron in rotary kiln a method, finishes according to the following steps: at first add siccative in containing the red soil nickel ore of planar water, mix, red soil nickel ore is dehydrated; Above-mentioned compound fragmentation, add reductive agent and grain nickel iron aggregating agent prepared therefrom then, mix; Again the above-mentioned material that mixes is directly sent into and carried out reducing roasting in the rotary kiln; Material is discharged in stove after the reducing roasting, through shrend cooling, broken, ball milling, uses the magnetic separator magnetic separation then, just can obtain high-grade grain nickel iron alloy.
The present invention has saved the equipment of equipment, milling equipment, pressure ball equipment and the dry pelletizing of oven dry red soil nickel ore, under equal industrial scale, project construction investment with have the related process investment now and compare, not only production technique reduces, environmental pollution also reduces, thereby the ferronickel cost that production technique of the present invention is produced reduces significantly, has solved ring formation in the rotary kiln formidable kiln of a specified duration simultaneously, influences the difficult problem of ordinary production.
The present invention only needs to add the siccative drying in red soil nickel ore, broken back adds reductive agent, the grain nickel iron aggregating agent prepared therefrom mixes, can carry out reducing roasting, shrend again, fragmentation, ball milling, magnetic separation after the reducing roasting can obtain nickel recovery height, nickel grain nickel iron of high grade.The present invention is owing to use the unslaked lime siccative, work to adjust basicity, the effect of grain nickel iron aggregating agent prepared therefrom is the liquid phase viscosity that reduces red soil nickel ore under the reduction temperature of red soil nickel ore and the high temperature, guarantee that red soil nickel ore can not produce sticking liquid phase, sticking kiln and form the long thick ring formation of kliner coating in rotary kiln, and improved reduction reaction speed, the nickel shot of highly dispersed around FeO gathered together, promote the grain nickel iron crystal to grow up, be gathered into big grain nickel iron, be convenient to the ball milling magnetic separation and separate, thereby improve the nickel grade and the rate of recovery.In addition, the present invention does not have excessive demand to the chemical ingredients of red soil nickel ore and the grade of nickel, is that all available explained hereafter of the present invention of nickel oxide ore or silicic acid nickel minerals goes out the higher-grade grain nickel iron, and the grade of nickel can reach 15-20%, and the rate of recovery can reach more than 90%.
The present invention has the advantage that production technique is simple, easy to operate, Production Flow Chart is short, the energy consumption of having saved the smelting ferronickel alloy, and cost is low.The grain nickel iron alloying pellet that the present invention produces can be directly as the stainless high quality raw material of electrosmelting.The rate of recovery height of nickel of the present invention is particularly compared with rotary kiln reduction magnetic separation ferronickel fine ore, has saved the cost of smelting ferronickel alloy, and economic benefit is considerable.The present invention is applicable to various grades and dissimilar red soil nickel ore reduction, has tangible economic benefit and social benefit, and promotion prospect is wide.
Description of drawings:
Fig. 1 is a process flow sheet of the present invention
Embodiment:
The present invention is the method for a kind of red soil nickel ore direct reduction grain nickel iron in rotary kiln, finish according to the following steps: at first in containing the red soil nickel ore of planar water, add siccative, mix, described siccative is calcareous unslaked lime or magnesia unslaked lime, the consumption of siccative is 5-10% of a red soil nickel ore weight, the siccative of adding make red soil nickel ore dehydrate to humidity be water content 8-10%.Then a compound that dehydrates being crushed to granular size is below the 5mm, adds reductive agent again and the grain nickel iron aggregating agent prepared therefrom mixes.Described reductive agent is a carbonaceous reducing agent, adopts coal dust or coke powder, and the weight of carbonaceous reducing agent is 3-9% of raw ore weight; Described grain nickel iron aggregating agent prepared therefrom is fluorine carbon cerium, monazite, szaibelyite and vermiculite, and the weight of grain nickel iron aggregating agent prepared therefrom is 3-9% of raw ore weight.Wherein the weight ratio between fluorine carbon cerium, monazite, szaibelyite, the vermiculite is 4:1.5:1:1.The above-mentioned material that mixes without grinding, make ball, oven dry, directly send into and carry out reducing roasting in the rotary kiln.Reduction temperature in the rotary kiln is controlled at 1250-1300 ℃, and the time of reducing roasting is 3-5 hours.The ferronickel oxide compound at high temperature oozes charcoal through being reduced into spongy ferronickel, runs foul of each other under the katalysis of grain nickel iron aggregating agent prepared therefrom He in the body of heater rotating process, is combined into grain nickel iron.After the reducing roasting, material is discharged in stove, be cooled to 25-50 ℃ through shrend, broken again, ball milling becomes 180-220 purpose fineness, use 2000-2500 Gausses' magnetic separator magnetic separation then, just can obtain high-grade grain nickel iron alloy, the grade of its nickel can reach 15-18%.
Embodiment 1
With aqueous red soil nickel ore powder (Ni1.41, Tfe8.8%) mix drying thoroughly with 5% calcareous unslaked lime, be crushed to below the 5mm, adding the carbonaceous reducing agent of raw ore weight 8% and 7% grain nickel iron aggregating agent prepared therefrom mixes, directly send into the rotary kiln reducing roasting, temperature is controlled at 1260 ℃, and the recovery time is 3 hours.After the reducing roasting, through shrend, carry out broken ball milling, use 2000 Gausses' magnetic separator magnetic separation then, obtain grain nickel iron, the nickel grade can reach 15.2%, and the rate of recovery of nickel reaches 90.1%.
Embodiment 2
With aqueous red soil nickel ore (Ni1.68, TFe10.2%) mix drying thoroughly with 7% calcareous unslaked lime, be crushed to below the 5mm, add the carbonaceous reducing agent of raw ore weight 9%, 8% grain nickel iron aggregating agent prepared therefrom mixes, directly enter the rotary kiln reducing roasting, temperature is controlled at 1280 ℃, and reducing roasting is after shrend, fragmentation, ball milling, use 2200 Gausses' magnetic separator magnetic separation then, obtain grain nickel iron, the nickel grade can reach 17.6%, and the rate of recovery of nickel reaches 90.5%.
Embodiment 3
With aqueous red soil nickel ore (Ni1.76, TFe11.0%) mix drying thoroughly with 6% magnesia unslaked lime, be crushed to below the 5mm, add the carbonaceous reducing agent of raw ore weight 7%, 6% grain nickel iron aggregating agent prepared therefrom mixes, directly enter the rotary kiln reducing roasting, temperature is controlled at 1300 ℃, and reducing roasting is after shrend, fragmentation, ball milling, use 2500 Gausses' magnetic separator magnetic separation then, obtain grain nickel iron, the nickel grade can reach 18.0%, and the rate of recovery of nickel reaches 92%.