Process for recovering zinc from hot-dip coating zinc ash

A hot-dip galvanizing and process technology, which is applied in the field of zinc secondary resource recovery, can solve the problems of low production energy consumption, low reaction reduction rate, low labor intensity, etc., and achieve the effects of friendly production environment, low labor intensity, and high purity of zinc products

Inactive Publication Date: 2011-02-23
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] The purpose of the present invention is to provide a hot-dip galvanizing ash recovery process with low production energy consumption, good crystal morphology, high reaction reduction rate, almost no environmental pollution, and low labor intensity, so as to overcome the existing hot-dip galvanizing ash recovery process. Method flaws

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  • Process for recovering zinc from hot-dip coating zinc ash

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Effect test

Embodiment 1

[0028] Zinc ash is passed through a 100-mesh sieve after dry grinding, and screened to obtain the oversize and undersize. Weigh 10.00 g of the sieved material, put it into a vacuum furnace, and keep the temperature at 450° C. for 30 minutes at a vacuum degree of 35 Pa, then take out the residual material in the vacuum furnace to form agglomerates. The bulk raw material was put into a vacuum furnace, and the vacuum degree in the furnace was 10 Pa, and the temperature was 750°C and distilled for 30 minutes, and 5.60 g of metal zinc could be recovered, and the quality of the residue was 3.30 g. The main component of the residue is zinc oxide according to XRD analysis. Take 10.00 g of the undersieve, wash with alkali and filter to obtain the filter residue. The main component of the filter residue is zinc oxide. Weigh 4.05g of the filter residue. The filter residue is mixed with 2.80g of calcium oxide, 1.16g of No. 75 ferrosilicon powder and 0.25g of calcium fluoride. In the fur...

Embodiment 2

[0030] Zinc ash is passed through a 100-mesh sieve after dry grinding, and screened to obtain the oversize and undersize. Weigh 10.00 g of the sieve, put it into a vacuum furnace, and distill for 30 minutes at a vacuum degree of 35 Pa and a temperature of 450° C., then take out the residual material in the vacuum furnace to form agglomerates. Put the bulk raw material into a vacuum furnace with a vacuum degree of 10 Pa, raise the temperature to 800°C, and distill for 50 minutes to obtain 5.75 g of metal (purity: 99.84%), and the quality of the residue is 3.26 g. The main component of the residue is zinc oxide according to XRD analysis. Take 10.00 g of the undersieve, wash with alkali and filter to obtain the filter residue. The main component of the filter residue is zinc oxide. Weigh 4.05g of the filter residue, 2.80g of calcium oxide, 1.16g of No. 75 ferrosilicon powder and 0.25g of calcium fluoride, and mix them uniformly to make agglomerates. Put the bulk raw material in...

Embodiment 3

[0032] Zinc ash is passed through a 100-mesh sieve after dry grinding, and screened to obtain the oversize and undersize. Weigh 10.00 g of the sieved material, put it into a vacuum furnace, and keep the temperature at 450° C. for 30 minutes at a vacuum degree of 35 Pa, then take out the residual material in the vacuum furnace to form agglomerates. Put the bulk raw material into a vacuum furnace with a vacuum degree of 10 Pa, raise the temperature to 800°C, and distill for 40 minutes. 5.71 g of metal (purity: 99.84%) can be recovered, and the mass of the residue is 3.21 g. The main component of the residue is zinc oxide according to XRD analysis. Take 10.00 g of the undersieve, wash with alkali and filter to obtain the filter residue. The main component of the filter residue is zinc oxide. Weigh 4.05g of the filter residue, 2.80g of calcium oxide, 1.16g of No. 75 ferrosilicon powder and 0.25g of calcium fluoride, and mix them evenly to form a lump, and put the lump raw materia...

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Abstract

The invention relates to a process for recovering zinc from hot-dip coating zinc ash. The process comprises the following steps of: separating the hot-dip coating zinc ash after dry grinding and screening to obtain an oversize product and an undersize product; removing bound water and a small amount of zinc chloride from the oversize product under the condition that the temperature is between 400 and 500 DEG C and the vacuum degree is 10 to 50 Pa; performing vacuum distillation on the oversize product under the condition that the temperature is between 650 and 800 DEG C and the vacuum degree is 10 to 30 Pa to obtain zinc; and performing alkali cleaning on the undersize product to remove chlorine, and then performing vacuum thermal reduction on the undersize product to obtain the zinc from zinc oxide by using ferrosilicon as a reducing agent and calcium oxide as a slagging agent under the condition that the vacuum degree is 10 to 30 Pa and the temperature is between 1,050 and 1,200 DEG C. The process has a high recovery rate for recovering the zinc from the hot-dip coating zinc ash, and the obtained zinc has a good crystallized shape.

Description

technical field [0001] The invention relates to the field of zinc secondary resource recovery, in particular to a process for recovering zinc from hot-dip galvanizing dust. Background technique [0002] The amount of zinc consumed by hot-dip galvanizing in the world accounts for about 50% of the total zinc consumption every year, and about 20% of the metal zinc forms zinc ash during the hot-dip galvanizing process. Zinc dust is formed when the surface of the zinc melt contacts the atmosphere and is oxidized and floats on the surface of the melt during the hot-dipping process. It is mainly composed of zinc oxide, metal zinc and zinc chloride. Generally, the mass fraction of zinc element in zinc ash is between 50% and 85%. If the zinc ash with high zinc content and large amount cannot be recycled well, it will cause a great waste of zinc resources. Therefore, with the decline of primary zinc ore reserves and the continuous growth of zinc consumption, it is of great significa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B19/30C22B7/04
CPCY02P10/20
Inventor 丘克强余超
Owner CENT SOUTH UNIV
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