Comprehensive recovery method of material with high chlorine and low zinc

A recycling method and material technology, applied to the improvement of process efficiency, photographic technology, instruments, etc., can solve the problems of high production cost, impact on zinc recovery, low zinc recovery rate, etc., achieve low energy consumption in oxidation roasting, and be easy to return to use , fast oxidation effect

Inactive Publication Date: 2018-12-21
贵州省兴安环保科技有限公司
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  • Abstract
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AI Technical Summary

Problems solved by technology

However, the process of electrolyzing zinc powder after alkali leaching is to use sodium hydroxide solution to leaching and then electrolyze zinc powder. The sodium chloride electrolyte obtained after enriching chloride ions to a certain concentration is difficult to return to use. It needs to be neutralized after zinc precipitation. The treatment of sodium chloride waste liquid not only affects the recovery of zinc, but also has a high cost of environmental protection treatment. At the same time, there are still problems such as high energy consumption, poor quality of zinc powder, and difficulty in expanding the scale after electrolysis of zinc powder after alkaline leaching.
The process of producing zinc sulfate by ammonia leaching also has the problem that it is difficult to return to use when the chloride ion enrichment content in the electrolytic raffinate is high, and it is difficult to purify and remove impurities in the ammonium chloride solution, and the solution is difficult to purify deeply. It is difficult for zinc to reach the quality standard of No. 1 zinc, and the electrolytic product is generally fragmented zinc, with a low casting rate and low economic benefits
Direct production of zinc sulfate crystals after ammonia leaching, because the zinc sulfate crystals produced by the process contain about 15% ammonia nitrogen, it can only be used in agriculture as zinc fertilizer, because it also contains a considerable amount of chlorine (mainly zinc chloride and ammonium chloride), long-term use will cause soil salinization, for this reason, also use P204 to extract zinc after leaching in sulfuric acid, sulfuric acid back extraction to obtain zinc sulfate solution, after concentration and purification, it is used for electric zinc production, so that chlorine The ions remain in the solution to separate from zinc, but because P204 extracts only about 50% of the zinc, the zinc content in the extracted liquid is still high, so it can only be returned for recycling. When the chloride ion content in the solution reaches 30g / When it is above L, it is difficult to recycle, and it can only be treated separately, which will lead to a large amount of waste residue and wastewater, low zinc recovery rate, and high production costs.

Method used

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  • Comprehensive recovery method of material with high chlorine and low zinc

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] The zinc ash produced by a zinc alloy production enterprise after being fried with ammonium chloride contains 25.6% Zn, 10.3% Cl, and 1.2% Al. Metal zinc is recovered by the following steps:

[0033](1) Zinc ash is granulated and added to the rotary kiln for oxidation and roasting. The oxidant is oxygen-enriched air with an oxygen content of 30%, and the air flow rate is 25-30m 3 / min, the calcination temperature is 650°C, the calcination time is 1.5h, and the calcination product containing Zn 38.1%, Cl 1.5%, Al 1.8% is obtained;

[0034] (2) The roasted product is leached by dilute sulfuric acid, and the leaching condition is H 2 SO 4 The concentration is 80g / L, liquid / solid=4, the leaching temperature is 85-90°C, the stirring time is 2.5h, the pH of the leaching end point is 2.5, and the obtained leachate contains 42.5g / L Zn, 1.2g / L Cl, and 0.85g / L Al ;

[0035] (3) Adding ammonium sulfate to the sulfuric acid leaching solution to salt out and crystallize ZnSO 4 ·...

Embodiment 2

[0039] Use the zinc ash produced by electric zinc melting and casting, and the material after fully frying with ammonium chloride and sieving the metal zinc is used as the raw material. The composition of the chlorine-containing zinc ash is Zn 31.4%, Cl 12.1%, and the metal zinc is recovered through the following steps:

[0040] (1) Zinc ash is added to the rotary kiln for oxidative roasting after granulation, and stirred with hydrogen peroxide, manganese dioxide and zinc ash respectively, and the dosage is theoretically oxidized Cl - 1.2 times of that, the roasting temperature is 600°C, and the roasting time is 1.5h, and roasted products containing Zn38.4%, Cl0.85% and Zn30.6%, Cl0.72% are respectively obtained;

[0041] (2) The roasted product containing Zn38.4%, Cl0.85% is leached with dilute sulfuric acid, and the leaching condition is H 2 SO 4 The concentration is 100g / L, liquid / solid=5, the leaching temperature is 85-90°C, the stirring time is 2h, the pH of the leaching...

Embodiment 3

[0046] A low-grade zinc oxide ore containing chlorine and sulfur contains 10.5% zinc, 1.6% chlorine, and 4.1% sulfur. Drum into the amount of 25-30m 3 / min, the temperature is 800 DEG C, roasting 2h, the roasted product contains zinc 15.5%, Cl 0.13%, S 0.016%, carry out dilute sulfuric acid leaching, ammonium sulfate salt precipitation crystallization, sulfation roasting, hot water then according to the condition of embodiment 1 Dissolving and purifying zinc powder, the obtained zinc sulfate solution contains Zn91.4g / L, Cl87mg / L, and the quality of electrolytic zinc is 0# zinc (Zn≧99.995%).

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Abstract

The invention relates to the technical field of wet metallurgy zinc recovery, in particular to a comprehensive recovery method of a material with high chlorine and low zinc. The comprehensive recoverymethod of the material with the high chlorine and the low zinc comprises the step that after the material with the high chlorine and the low zinc is subject to oxidizing roasting, dilute sulphuric acid leaching, ammonium sulfate salting-out crystal, sulphation roasting, hot water dissolution and purification and impurity-removing, more than 99% of chlorine removes from the material with high chlorine and the low zinc, the enrichment of the zinc content can reach more than three times, recovery of metal zinc is facilitated through leaching and electrolysis, and the effect of low cost, high efficiency and obvious economic and social benefits is achieved.

Description

technical field [0001] The invention relates to the technical field of zinc recovery by hydrometallurgy, in particular to a comprehensive recovery method for high-chlorine and low-zinc materials. Background technique [0002] A considerable amount of zinc dust and zinc dross will be produced in the production of zinc alloy, die-cast zinc alloy and electrolytic zinc sheet melting and casting; this type of zinc dust and zinc dross has the characteristics of high chlorine content, so it is difficult to be directly used in electrolytic zinc Production, if the rotary kiln is used for redox roasting, since the volatilization temperature of the rotary kiln is 1100-1250°C, most of the chloride components will volatilize into the zinc oxide dust collection; if acid leaching or neutral solution is used to leach zinc oxide, the chlorine element It is easy to dissolve in the solution, resulting in high removal cost, and the excessive concentration of chloride ions in zinc sulfate seriou...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B1/02C22B1/06C25C1/16C22B19/20C22B19/30
CPCC22B1/02C22B1/06C22B7/001C22B7/006C22B7/007C22B19/20C22B19/30C25C1/16Y02P10/20
Inventor 李世平王志斌韦国龙卢宇
Owner 贵州省兴安环保科技有限公司
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