The method of fine zinc sulfide is prepared in a kind of closed cycle
Technical field
The invention belongs to technical field of fine, relate to a kind of preparation method of zinc sulphide, especially relate to a kind of method that fine zinc sulfide is prepared in closed cycle.
Background technology
Zinc sulphide easily disperses, not easily reunite, for the white of neutrality, and there is good optical property, the component of Chang Zuowei thermoset(ting)plastic, thermoplastics, reinforcing fiber glass, fire retardant, synthetic chloroprene rubber and dispersion agent, is widely used in semi-conductor, pigment, photo-luminescent devices, solar cell, infrared detector, fiber optics communication etc.
In prior art, zinc sulphide production and preparation adopts zink sulphide purification or hydrogen sulfide to pass into the method for zinc solution reaction usually, complex manufacturing, due to the oxygenizement in the insufficient and storage process of purification, separation, zinc sulphide powder is usually containing a small amount of sulfate radical, and zinc sulphide transformation efficiency is about 50%, transformation efficiency is very low, particle is thick and particle diameter is uneven, more because hydrogen sulfide has hypertoxicity, makes to there is huge potential safety hazard in production; And " three wastes " quantity discharged is large, the harm caused environment is too serious, makes production be difficult to development, and output is difficult to increase, and faces very serious sewage handling problem.
Chinese patent CN101205077A discloses a kind of method preparing barium sulfate and zinc sulphide, and wherein the preparation of zinc sulphide is the zinc oxide ZnO and sulfuric acid H that adopt zinc-containing ores calcining obtained
2sO
4reaction, reaction solution obtains zinc sulfate ZnSO through purification impurity
4solution, then pure zinc sulfate ZnSO
4solution and Sodium Sulphide Na
2s reacts, and reaction product is separated through press filtration and obtains zinc sulphide.The zinc sulphide that the method obtains is thick product, and containing a small amount of sodium sulfate in product, purity is low, and price is low, and purposes is single, the main raw material being used as smelting zinc.
Along with industrial expansion, the purposes of fine zinc sulfide in the fields such as semi-conductor, pigment, photo-luminescent devices, solar cell, infrared detector, fiber optics communication is increasingly extensive, existing fine zinc sulfide can not be met the need of market, therefore, in the urgent need to a kind of simple and easy to do, environment friendly and pollution-free fine zinc sulfide preparation method.
Summary of the invention
For solving the problem, the object of this invention is to provide a kind of method that fine zinc sulfide is prepared in closed cycle, its raw materials cost is low, and technique is simple, easy to operate, the waste water in production process is got back in original production process and reuses, realize closed cycle.
For achieving the above object, the present invention adopts following technical scheme:
A method for fine zinc sulfide is prepared in closed cycle, and it comprises the following steps:
Step 1, by ZnO pressed powder and H
2sO
4solution mixing adds in the first reactor, wherein ZnO pressed powder and H
2sO
4solution quality is than being 1:1.5 ~ 2.5, H
2sO
4mass percent concentration is 20 ~ 25%, after reacting 25 ~ 35min, regulates the rear solution pH value of reaction to be 5.0 ~ 5.5, obtains the ZnSO adulterated under 65 ~ 75 DEG C of temperature condition
4solution; Then, to the ZnSO of doping
4solution carries out removal of impurities process, removing ZnSO
4impurity Nickel in solution, molybdenum, chromium, copper, lead and iron, obtain the pure ZnSO that foreign matter content is less than 0.02%
4solution;
Step 2, the pure ZnSO will obtained in step 1
4solution and Na
2s solution adds in the second reactor, wherein ZnSO
4solution and Na
2s solution quality ratio is 2 ~ 2.5:1, Na
2s mass percent concentration is 20 ~ 25%, and reaction product adopts pressure filter to carry out first time press filtration and is separated, and obtains filter cake moisture and is not more than 30% and Na
2sO
4content is not more than the solids crude zinc sulphide of 5%;
Step 3, in rinse bath with the thick zinc sulphide of clean water, the gravity after cleaning controls between 0 ~ 0.2, wherein Na
2sO
4content is less than 0.15%;
Mixed solution in step 4, rinse bath adopts pressure filter to carry out second time press filtration and is separated, the solid zinc sulphide extracted is dry under temperature 100 ~ 110 DEG C of conditions, roast 30 ~ 50min under 745 ~ 755 DEG C of high temperature, carry out height with micronizer mill again to pulverize, obtaining granularity is 1000 ~ 1500 object fine zinc sulfide products;
After mixed solution in step 5, rinse bath adopts pressure filter to carry out second time press filtration separation, dialysis liquid out, namely the waste water containing mass percentage 0.7 ~ 1.7% sodium sulfate and mass percentage 0.75 ~ 0.85% zinc sulphide is sent in the first reactor, with ZnO pressed powder and H
2sO
4solution mixes, and realizes closed cycle.
Chemical equation
ZnO+H
2SO
4→ZnSO
4+H
2O
ZnSO
4+Na
2S→ZnS+Na
2SO
4
Above-mentioned closed cycle is prepared in the method for fine zinc sulfide, and ZnO pressed powder is with zinc ore or contain Zn scrap returns for raw material.
The method of fine zinc sulfide is prepared in described closed cycle, in step 1, to the ZnSO of doping
4solution carries out removal of impurities treatment step, by the ZnSO of doping
4solution puts into deblending slot, adds oxygenant H in deblending slot
2o
2oxidation ZnSO
4impurity iron in solution; Again by the ZnSO after removal of impurities
4solution puts into displacing device, adds zinc powder, and at temperature 85 ~ 95 DEG C and agitation condition, reaction 30 ~ 40min, carries out filtering separation, removing ZnSO
4impurity Nickel in solution, molybdenum, chromium, copper, lead and iron.
The method of fine zinc sulfide is prepared in described closed cycle, in step 1, to the ZnSO of doping
4solution carries out removal of impurities treatment step and carries out 1 ~ 3 time.
The method of fine zinc sulfide is prepared in described closed cycle, in step 3, with 45 ~ 55 DEG C of thick zinc sulphide several times of clean water in rinse bath.
Owing to adopting technical scheme as above, the present invention has following superiority:
The method of fine zinc sulfide is prepared in this closed cycle, its technique is simple, easy to operate, cost of investment is low, crude zinc oxide materials wide material sources, require not strict to starting material, the waste water produced in zinc sulphide production process can be sent into original production process, continue to utilize, realize without waste water, exhaust gas emission, environmentally friendly, saving water resource, byproduct yield is high, obtained fine zinc sulfide quality product is up to state standards requirement, economic benefit improves 10 ~ 20%, solve waste water in traditional processing technology, exhaust gas emission problem and waste water reclamation cost high, consume energy large drawback.
Accompanying drawing explanation
Fig. 1 is process flow sheet of the present invention.
Embodiment
Can be described in further detail the present invention with reference to the process flow sheet in Fig. 1 and following examples; But following examples are only illustrations, and the present invention is not limited to these embodiments.
Embodiment 1
Step 1, in the first reactor, add clear water 150ml, under agitation add the dense H that 53ml massfraction is 98%
2sO
4being mixed with mass percent concentration is 20% rare H
2sO
4solution, then add 50g crude zinc oxide materials (containing ZnO 85%), ZnO pressed powder and H
2sO
4solution quality, than being 1:2.25, after reacting 32min, regulating the rear solution pH value of reaction to be 5.0, obtains the ZnSO adulterated under 65 DEG C of temperature condition
4solution; Then, by the ZnSO of doping
4solution puts into deblending slot, adds oxygenant H in deblending slot
2o
2oxidation ZnSO
4impurity iron in solution; Again by the ZnSO after removal of impurities
4solution puts into displacing device, adds zinc powder, and at temperature 92 DEG C and agitation condition, reaction 30min, carries out filtering separation, removing ZnSO
4impurity Nickel in solution, molybdenum, chromium, copper, lead and iron, through chemical examination, test, obtain the pure ZnSO that foreign matter content is less than 0.02%
4solution;
Step 2, the pure ZnSO will obtained in step 1
4solution and 40.7g Na
2s solution adds in the second reactor, wherein ZnSO
4solution and Na
2s solution quality is than being 2.06:1, Na
2s mass percent concentration is 20%, and reaction generates ZnS 44.85g, Na
2sO
465.37g, reaction product adopts pressure filter to carry out first time press filtration and is separated, and obtains filter cake moisture and is 25% and Na
2sO
4content is the solids crude zinc sulphide of 4%;
Step 3, in rinse bath with the thick zinc sulphide of clean water 3 times, the gravity after cleaning is 0.15, wherein Na
2sO
4content is less than 0.15%;
Mixed solution in step 4, rinse bath adopts pressure filter to carry out second time press filtration and is separated, the solid zinc sulphide extracted is dry under temperature 100 DEG C of conditions, roast 50min under 750 DEG C of high temperature, carry out height with micronizer mill again to pulverize, obtaining granularity is 1000 ~ 1500 object fine zinc sulfide product 44.7g, containing Na in fine zinc sulfide
2sO
40.18g;
After mixed solution in step 5, rinse bath adopts pressure filter to carry out second time press filtration separation, dialysis liquid out, the waste water namely containing 1.5% sodium sulfate, 0.79% zinc sulphide is sent in the first reactor, realizes closed cycle.
Embodiment 2
Step 1, in the first reactor, add waste water 150ml containing 1.5% sodium sulfate, 0.79% zinc sulphide, under agitation add the dense H that 53ml massfraction is 98%
2sO
4being mixed with mass percent concentration is 20% rare H
2sO
4solution, then add 50g crude zinc oxide materials (containing ZnO 85%), ZnO pressed powder and H
2sO
4solution quality, than being 1:2.25, after reacting 28min, regulating the rear solution pH value of reaction to be 5.2, obtains the ZnSO adulterated under 70 DEG C of temperature condition
4solution; Then, by the ZnSO of doping
4solution puts into deblending slot, adds oxygenant H in deblending slot
2o
2oxidation ZnSO
4impurity iron in solution; Again by the ZnSO after removal of impurities
4solution puts into displacing device, adds zinc powder, and at temperature 85 DEG C and agitation condition, reaction 35min, carries out filtering separation, removing ZnSO
4impurity Nickel in solution, molybdenum, chromium, copper, lead and iron, through chemical examination, test, obtain the pure ZnSO that foreign matter content is less than 0.02%
4solution;
Step 2, the pure ZnSO will obtained in step 1
4solution and 40.7g Na
2s solution adds in the second reactor, wherein ZnSO
4solution and Na
2s solution quality is than being 2.06:1, Na
2s mass percent concentration is 20%, and reaction generates ZnS 44.84g, Na
2sO
475.40g, reaction product adopts pressure filter to carry out first time press filtration and is separated, and obtains filter cake moisture and is 25% and Na
2sO
4content is the solids crude zinc sulphide of 5%;
Step 3, in rinse bath with the thick zinc sulphide of clean water 3 times, the gravity after cleaning is 0.15, wherein Na
2sO
4content is less than 0.15%;
Mixed solution in step 4, rinse bath adopts pressure filter to carry out second time press filtration and is separated, the solid zinc sulphide extracted is dry under temperature 100 DEG C of conditions, roast 45min under 745 DEG C of high temperature, carry out height with micronizer mill again to pulverize, obtaining granularity is 1000 ~ 1500 object fine zinc sulfide product 44.7g, containing Na in fine zinc sulfide
2sO
40.18g;
After mixed solution in step 5, rinse bath adopts pressure filter to carry out second time press filtration separation, dialysis liquid out, the waste water namely containing 1.5% sodium sulfate, 0.79% zinc sulphide is sent in the first reactor, realizes closed cycle, without discharge.
What the per-cent in above-mentioned two embodiments referred to is mass percent.