CN1003008B

CN1003008B - Technology for preparation of li2co3 by treating lithium-loaded mica with k2so4

Info

Publication number: CN1003008B
Application number: CN85101989A
Authority: CN
Inventors: 李明乾
Original assignee: Guangzhou Research Institute of Non Ferrous Metals
Current assignee: Guangzhou Research Institute of Non Ferrous Metals
Priority date: 1985-04-01
Filing date: 1985-04-01
Publication date: 1989-01-04
Also published as: CN85101989A

Abstract

The present invention relates to a technology for carrying out two-step leaching treatment to lepidolite. The present invention has the key point that potassium in lepidolite is used for extracting lithium and recovering various elements, such as potassium, sodium, aluminum, silicon, rubidium and cesium in lepidolite. In the method, lepidolite and potassium sulfate are mixed and calcined, one-step four-stage countercurrent leaching is carried out, and lithium carbonate products are obtained by purifying and precipitating leachate. Various elements in lepidolite are recovered through the two-step four-stage countercurrent leaching of leached dregs. The method has the advantages of high productivity for producing lithium carbonate, low energy consumption, no pollution, greatly lowered cost and construction investment saving, and existing devices for producing lithium carbonate by a lime method can be utilized.

Description

Processing method with preparation of Li 2 CO 3 by treating lithium-loaded mica with K 2 SO 4

The invention belongs to lithionite is carried out two sections chemical metallurgy processing methodes that leach processing.

Generally produce the production method of Quilonum Retard, limestone-based process is arranged, sulfuric acid process and vitriolate of tartar method from ore.The domestic limestone-based process that uses is mostly now handled lithionite, though this method can be used for industrial production on a large scale, its inevitable shortcoming is arranged, as it is higher to require concentrate to contain lithium, requires granularity very little to furnace charge and agglomerate, and it is very rare that agglomerate leaches back solution.Thereby steam output is big, and the mud that leaches has coherency, easily caking and often make device fails.Its maximum shortcoming is exactly that production capacity is little, and is very uneconomical, according to present international market price Li per ton ₂CO ₃Be 7000 yuan of calculating, the cost that limestone-based process is produced Quilonum Retard has substantially exceeded international market price.Therefore, from production capacity and cost two aspects, the present invention has had lot of advantages.

Aspect vitriolate of tartar method processing lithionite, as the factory of " external lithium rubidium caesium industry " middle Germany of introducing in Frankfort, be with after the lithionite roasting, water leaches Lithium Sulphate, leached mud discards, purification of leaching liquor removes de-iron, behind the manganese, be settled out Quilonum Retard with soda, and Czechoslovakian factory has adopted also similar vitriolate of tartar method to handle the fluorine zinnwaldite, produced Quilonum Retard, its concentrate and vitriolate of tartar were in 10: 3.5 ratio batch mixes, 900 ℃ of following roastings, burn piece and leach, purify and then iron is oxidized to trivalent with potassium permanganate, with methyl alcohol the Excessive Manganese reduction is made it precipitation again, filter after liquid and be settled out Quilonum Retard with saturated solution of potassium carbonate.

Above-mentioned vitriolate of tartar method all is one section and leaches the processing lithionite, its remarkable shortcoming is to consume a large amount of sylvite and sylvite recovery difficulty on the one hand, be on the other hand: generally produce one ton of Quilonum Retard and will produce tens tons of leached muds, severe contamination surrounding environment not only after its slag discards, and a lot of useful elements can not reclaim in the slag, therefore are not used.Result according to the retrieval, nearly two during the last ten years, and the vitriolate of tartar method leaches for one section to be handled lithionite and produces the technical process of Quilonum Retard and fail to be improved and significant development always.

Purpose of the present invention is exactly in order to save the energy and raw material, avoids useful element in environmental pollution and the comprehensive utilization lithionite, has proposed two sections leaching processing of employing vitriolate of tartar method lithionite and has produced Quilonum Retard, the comprehensive useful element that reclaims wherein.

Main points of the present invention are: utilize the potassium in the lithionite, propose the lithium in the lithionite, when producing Quilonum Retard, reclaim potassium, sodium, aluminium, silicon, rubidium, caesium various element compound in the lithionite, leached mud obtains comprehensive utilization, and detailed process flow please be seen this Figure of description.

Concrete grammar of the present invention is: with levigate extremely-60 orders of lithionite, equal 1 to 0.5 with vitriolate of tartar by ratio of components and mix, carry out roasting, maturing temperature is 930 ℃, roasting time 2 hours.It is levigate to-60 orders to burn piece after the roasting, carries out four-stage counter-current and leaches, and the liquid-solid ratio of leach liquor is 1.5 to 1, and extraction time is to get final product in 40～50 minutes.The leaching yield of lithium is that 85.3%～89.4%(is by slag).The X-ray analysis of leached mud shows that the composition of leached mud is white mica and white garnet, and the concentration that leaches Quilonum Retard in the leach liquor of back reaches 30～32g/L.

The cleansing phase of leach liquor divides two sections to regulate the pH value, transfers pH=7, removes Fe, Al for first section, after then solution being filtered, transfer pH=12 again, remove Mg, Mn, Ca etc., promptly get scavenging solution, scavenging solution is heated to more than 90 ℃, calculates by excessive 5%, join in the scavenging solution with saturated sodium carbonate solution, Quilonum Retard promptly precipitates, its deposition rate is 66.29～74.99%, and after the throw out oven dry, wherein lithium carbonate containing reaches 99%.

Feature of the present invention is exactly that the slag after one section leaching is leached again, i.e. two sections leachings.Two sections leachings be with dilute sulphuric acid 0.5～1.5M or be transferred to the alum that acidity is 0.5～1.5M after liquid, leached mud is carried out four-stage counter-current to be leached, extraction temperature is 90 ℃～100 ℃, each element all can leach, almost all enter in the solution as Li, Na, K, Rb, Cs, Al, Fe etc., two sections leached muds are SiO ₂, its purity is 96～97%.

The recovery of each element divides four steps in two sections leach liquors:

1. one-tenth alum: with two sections leach liquor evaporation concentration, crystallization impurity removal alum filters, and filtrate is liquid behind the alum.After adjusting acidity, return and be used for two sections leachings, lithium wherein is enriched to that to a certain degree the back is recyclable, and assorted alum is dissolved in water, alum water liquid, as extracting Al(OH) ₃, Na ₂SO ₄, K ₂SO ₄, (Rb, Cs) ₂SO ₄Feed liquid.

2. reclaim Al(OH) ₃: reclaim Al(OH) ₃Be based on following reaction: K ₂SO ₄Al ₂(SO ₄) ₃+ 24H ₂O+6NH ₄OH=2Al(OH) ₃↓+3(NH ₄) ₂SO ₄+ K ₂SO ₄+ 24H ₂O adds ammoniacal liquor and make its decomposition in alum water liquid, is settled out Al(OH) ₃Get K after the filtration ₂SO ₄, Na ₂SO ₄, (NH ₄) ₂SO ₄And (Rb, Cs) ₂SO ₄Mixing solutions.

3. from mixed solution, reclaim K ₂SO ₄, Na ₂SO ₄, these two kinds of compounds reclaim with the thermostatical crystallization method.Use and decompose Al(OH) ₃After mother liquor the time, not high because of wherein containing the sodium amount, can directly obtain purer K ₂SO ₄(reaching more than 95%), but with the mother liquor behind the aforementioned purification precipitation Quilonum Retard, only can obtain purity and be 65%～70% vitriolate of tartar, utilize these two kinds of vitriolate of tartar to allocate to 70%, return the roasting of preparing burden of roasting stage and lithionite, the potassium in the lithionite is recycled.

4.(Rb, Cs) ₂SO ₄Recovery: reclaim it with known extraction process.

The present invention is than existing Quilonum Retard production method, has advantages such as the streams flux is little, the low production capacity of oil consumption is big, under identical initial cost, improves 3.5 times than the production capacity of limestone-based process.And cost of the present invention is lower than 7000 yuan/TLi ₂CO ₃, economic benefit is remarkable especially.The K of Hui Shouing in process of production ₂SO ₄, Na ₂SO ₄Can recycle on stream.All the other byproducts such as SiO ₂, Al(OH) ₃, (NH ₄) ₂SO ₄, (Rb, Cs) ₂SO ₄Deng selling separately.Another big characteristics of the present invention are: can utilize the equipment of using the limestone-based process flow process in the present production, transform a little, can put into operation, thereby save initial cost greatly.

Example: the main component of lithionite is:

Composition	Li ₂O	Na ₂O	K ₂O	Ca ₂O	Rb ₂O	SiO ₂	Al ₂O ₃
								Content (%)	3.863	2.965	7.492	0.254	1.02	52.99	24.42

Lithionite is levigate to-60 orders, press lithionite: K ₂SO ₄=1: 0.5 batching, roasting 2 hours, temperature is 930 ℃.Burn piece and carry out the four-stage counter-current leaching, liquid-solid ratio is 1.5: 1, leaches 40 minutes, and temperature is a normal temperature, and the leaching yield of lithium reaches 89.44%, Li in the leach liquor ₂The concentration of O reaches 32g/L, first section accent of purification of leaching liquor pH=7 transfers pH=12 to remove Mg, Mn, Ca etc. after removing Fe, Al, filtration again, and decontamination effect improving is as follows:

Fe reduces to 0.003g/L by 0.34g/L;

Al reduces to 0.005g/L by 0.1g/L;

Mn reduces to 0.0006g/L by 0.75g/L;

Mg is reduced to＜0.001g/L by 0.18g/L;

Ca reduces to 0.0014g/L by 0.04g/L;

Scavenging solution is heated to more than 90 ℃, adds excessive 5% saturated Na ₂CO ₃Solution, Li ₂CO ₃Promptly precipitate, its deposition rate reaches 74.5%, after the oven dry, and Li ₂CO ₃Purity be higher than 98%.

The composition of above-mentioned leached mud is:

Composition

Li

Na

K

Rb

Cs

Fe

Al ₂O ₃

SiO ₂

Content (%)

0.21

0.90

14.38

1.56

0.19

1.23

19.38

Do not analyze

With dilute sulphuric acid 1M or be transferred to behind the alum that acidity is 1M liquid and leached mud is carried out four-stage counter-current leach, extraction temperature is 90 ℃～98 ℃, and each element is all entered solution by leaching, leached mud SiO ₂Purity be 97%.

The leaching yield of each element in two sections leachings is as follows:

Element

Li

Na

K

Rb

Cs

Fe

Al ₂O ₃

Two sections leaching yields (%)

99.97

82.75

97.1

96.31

/

95.31

94.7

Leach the back and reclaim various elements by four-step method described in the preceding specification sheets.The wastage rate and the rate of recovery of each operation lithium are as follows:

The rate of recovery (%) of the wastage rate of lithium (%) lithium

Get the raw materials ready, calcining process 6.64 93.37

Leach operation 1 99

Cleaning section 2.11 97.89

Precipitation operation 3.18 96.82

The total yield of lithium: 93.37% * 99% * 97.89% * 96.8%=90.4%.

Claims

1, a kind of processing method with preparation of Li 2 CO 3 by treating lithium-loaded mica with K 2 SO 4, it is behind the mixture of roasting lithionite and vitriolate of tartar, will burn that piece is levigate to carry out one section adverse current leaching, purification adds 30%Na more then ₂CO ₃Solution gets Li ₂CO ₃Precipitation, centrifugation and centrifuge washing should precipitate, and final drying draws Li ₂CO ₃Product, feature of the present invention is: liquid carries out two sections four-stage counter-current and leaches behind the alum that the leached mud after one section leaching is 0.5～1.5M with dilution heat of sulfuric acid or the acidity of 0.5～1.5M again, and its extraction temperature is 90～100 ℃; Two sections leach liquors flash to alum, after the filtration liquid and assorted alum behind the alum, liquid returns and is used for two sections leachings behind the alum, assorted alum is dissolved in water into alum water liquid, then adds ammoniacal liquor and make its decomposition in alum water liquid, reclaims Al(OH) ₃; Reclaim (NH with constant temperature ground again ₄) ₂SO ₄, K ₂SO ₄, Na ₂SO ₄, K wherein ₂SO ₄Return and lithionite concentrate batching, reclaim Rb with extraction process at last ₂SO ₄And Cs ₂SO ₄

2, the method for claim 1 is characterized in that behind the alum that the Li in the liquid is enriched to that to a certain degree the back is recyclable.