CN1314492C

CN1314492C - Two-stage grinding-classifying process for preparing alumina pulp

Info

Publication number: CN1314492C
Application number: CNB2004100223881A
Authority: CN
Inventors: 王其超; 王树超; 张明渊
Original assignee: Guiyang Aluminum Magnesium Design and Research Institute Co Ltd
Current assignee: Guiyang Aluminum Magnesium Design and Research Institute Co Ltd
Priority date: 2004-04-23
Filing date: 2004-04-23
Publication date: 2007-05-09
Anticipated expiration: 2024-04-23
Also published as: CN1569339A

Abstract

The present invention discloses a classification technique for preparing Al2O3 ore pulp by ore grinding of two grinders. Bauxite and lime are added to a rod grinder for coarse grinding, ground coarse ore pulp enters a pump pool, and classified bottom flow which is classified by a hydrocyclone entirety enters a ball grinder for fine grinding; an amount of alkali liquid is used for regulating the optimal liquid-solid ratio in the grinder, extracted ore pulp enters the same pump pool, the mixed ore pulp content is from 470 to 520 g/L by adding alkali liquid, mixed ore pulp in the pump pool is conveyed to the hydrocyclone for classification by a speed regulation pulp pump, the bottom flow enters the ball grinder for regrinding, and the overflowed pulp is finished ore pulp. Because of large coarse grinding capacity of the rod grinder, the grinding performance of the ball grinder is good, and the fineness of the finished ore pulp is ensured. Thereby, the dissolution rate of Al2O3 is improved, the overground phenomenon is reduced, the yield is increased, and the energy consumption is reduced.

Description

Two sections mill ore grinding-grading technologies of alumina pulp preparation

Technical field:

The present invention relates to a kind of technology of alumina producing slurry preparation.

Background technology:

At AL ₂O ₃In the production process, it generally all is to use the ball mill ore grinding that bauxite prepares ore pulp, the spiral classifier classification, also use the ball mill ore grinding individually, the primary grinding classification flow process of hydroclone classification, its finished product slurry fineness is inhomogeneous, and thick (63 μ m content have only 55～60%), send to the high pressure stripping, AL ₂O ₃Dissolution rate only reaches about 87%.In classification process, the spiral classifier classification, classification efficiency only reaches 50～60%, causes 40～50% qualified products classifications not come out, and produces the phenomenon of regrinding, and output is carried not high, and energy consumption increases.The five big alumina producers that China has built, slurry preparation all is the weak link in the production process.Generally adopt the grinding grading technique of one section mill-spiral classifier, although these ores are good molten relatively, mog put broad, and actual index does not all reach requirement, qualification rate about 10%, AL ₂O ₃Dissolution rate only reaches about 87%.The spiral classifier classification efficiency is low, adds the corase grind of ore, and fine grinding is all carried out in same grinding machine, and overground phenomenon takes place the part ore, and the ability of grinding machine is not in full use, and production capacity is low, and the ore grinding power consumption increases.Spiral classifier belongs to the heavy load running device, off-axis is arranged and kill phenomenon, and fault is more.

Summary of the invention:

The objective of the invention is to: a kind of one section rod mill open-circuit grinding is provided, the two sections closed circuit ore deposit of ball mill mills, the new technological flow of hydroclone classification is to improve AL ₂O ₃Dissolution rate, and reduce qualified products and be back to ball mill and regrind, reduce the phenomenon of regrinding, output is improved, energy consumption reduces.

The present invention is achieved in that bauxite, lime adds rod mill in 100: 7～9 ratios and roughly grinds, and adding proper quantity of lye, liquid-solid ratio is 0.4～0.8 in the control mill, the control slurry temperature is at 80～90 ℃, rough slurry fineness 100%＜3000 μ m that grinds, 80%＜650～1000 μ m, 25～35%＜63 μ m enter the pump pond, classification underflow behind hydroclone classification all enters the ball mill fine grinding, the best liquid-solid ratio of regulating under 80～90 ℃ temperature in the mill with proper quantity of lye is 0.4～0.8, the ore pulp of discharging also enters same pump pond, and add alkali lye control temperature at 80～90 ℃, make mixed ore pulp be contained in 470～520g/L admittedly, with the speed governing slush pump mixed ore pulp in pump pond is delivered to hydrocyclone and carry out classification, classification efficiency is more than 80%; Wherein underflow enters ball mill and regrinds, and overflow is the finished product ore pulp.

The present invention compared with prior art because rod mill corase grind ability is big, the ball mill grinding performance is good, hydroclone classification efficient height is easy and simple to handle, guarantees the finished product slurry fineness, thereby makes AL ₂O ₃Dissolution rate be improved, and reduce qualified products and be back to ball mill and regrind, reduce overground phenomenon, output is improved, energy consumption reduces.The percentage composition of slurry fineness-63 μ m is higher more than 10% than one section mill, and classification efficiency is more than 80%, and dissolution rate reaches 93～94%.Compare the 6.22 kilowatt hours/ton ore deposit of economizing on electricity with one section mill.

The specific embodiment

Embodiments of the invention: with bauxite (lumpiness is less than 25mm), lime (lumpiness is less than 50mm) is roughly ground in 100: 8 ratio adding rod mill, and adding proper quantity of lye, the control temperature is at 80～90 ℃, guarantee that the best liquid-solid ratio of ore grinding is 0.4～0.8 in the mill, the rough slurry that grinds (fineness 100%＜3000 μ m, 80%＜650～1000 μ m, 25～35%＜63 μ m) enters the pump pond.Classification underflow behind hydroclone classification (coarse sand) all enters ball mill fine grinding (this moment, amount of solid was 2.5～3.5 times of ore amount that add rod mill), the best liquid-solid ratio of regulating in the mill with proper quantity of lye (80～90 ℃ of temperature) is 0.4～0.8, the ore pulp of discharging also enters same pump pond, and adding alkali lye (80～90 ℃ of temperature), make mixed ore pulp be contained in 470～520g/L admittedly, with the speed governing slush pump mixed ore pulp in pump pond is delivered to hydrocyclone and carry out classification (keeping stable feed pressure), classification efficiency is more than 80%.Wherein, (enter ball mill and regrind admittedly be contained in 1100～1250g/L), overflow is finished product ore pulp (admittedly being contained in 200～280g/L, fineness-63 μ m 70% ± 5% ,-315 μ m 98.75% ,-500 μ m100%) to underflow.

Claims

1, a kind of two sections mill ore grinding-grading technologies of alumina pulp preparation, it is characterized in that: with bauxite, lime adds rod mill in 100: 7～9 ratios and roughly grinds, and adding proper quantity of lye, liquid-solid ratio is 0.4～0.8 in the control mill, the control slurry temperature is at 80～90 ℃, rough slurry fineness 100%＜3000 μ m that grinds, 80%＜650～1000 μ m, 25～30%＜63 μ m enter the pump pond, classification underflow behind hydroclone classification all enters the ball mill fine grinding, the liquid-solid ratio of regulating under 80～90 ℃ temperature in the mill with proper quantity of lye is 0.4～0.8, the ore pulp of discharging also enters same pump pond, and adds alkali lye control temperature at 80～90 ℃, makes mixed ore pulp be contained in 470～520g/L admittedly, with the speed governing slush pump mixed ore pulp in pump pond is delivered to hydrocyclone and carry out classification, classification efficiency is more than 80%; Wherein underflow enters ball mill and regrinds, and overflow is the finished product ore pulp.