Treatment method for phosphoric acid arsenic-removed slag

A treatment method and arsenic removal technology, applied in chemical instruments and methods, arsenic compounds, inorganic chemistry, etc., can solve the problems of waste of resources and increase the burden on enterprises

Active Publication Date: 2014-03-26
CHENGDU INTERMENT TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Phosphoric acid dearsenic slag not only contains useful arsenic, but also contains valuable metals such as lead, chromium, nickel, etc. The above-mentioned hoarding and storage not only increases the burden on enterprises, but also causes waste of resources

Method used

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  • Treatment method for phosphoric acid arsenic-removed slag

Examples

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Comparison scheme
Effect test

Embodiment 1

[0013] A phosphoric acid production enterprise produces primary phosphoric acid by thermal method. In order to remove arsenic in primary phosphoric acid, a de-arsenic tower is installed in the production process, and P is added to the de-arsenic tower. 2 S 5 React with primary phosphoric acid to generate more stable As 2 S 3 , so as to achieve the purpose of arsenic removal. The waste residue generated in the arsenic removal tower is the phosphoric acid arsenic removal residue to be treated in this embodiment. After inspection, the phosphoric acid dearsenic slag contains As2 S 3 10.32%, Pb1.46mg / kg, Cr2.12mg / kg, Ni2.89mg / kg, Cd0.254mg / kg. Now the phosphoric acid dearsenic slag is dried (the water content is reduced to about 10%), and sent to the rotary kiln for oxidation and roasting, such as figure 1 As shown, the air is blown into the rotary kiln through the blower 500, and the reaction temperature is controlled by the joint control of the ventilation speed and the detec...

Embodiment 2

[0015] The phosphoric acid dearsenic slag is the same as in Example 1. Now the phosphoric acid dearsenic slag is dried (the water content is reduced to about 10%), and sent to the rotary kiln for oxidation and roasting, such as figure 1 As shown, the air is blown into the rotary kiln through the blower 500, and the reaction temperature is controlled by the joint control of the ventilation speed and the detection temperature in the kiln, and the reaction temperature is strictly controlled at 530-570°C, so that As 2 S 3 Reacts with oxygen and fully converts to As 2 o 3 and SO 2 Gas; before sending the high-temperature furnace gas produced by the rotary kiln into the first flue gas filter 200, first inject inert preheating gas into the first flue gas filter 200 through the blowback device 213 to filter the first flue gas The sintered inorganic porous material filter element in the device 200 is preheated to about 150°C, and then the high-temperature dust-containing furnace ga...

Embodiment 3

[0017] The phosphoric acid dearsenic slag is the same as in Example 1. Now the phosphoric acid dearsenic slag is dried (the water content is reduced to about 10%), and sent to the rotary kiln for oxidation and roasting, such as figure 1 As shown, the air is blown into the rotary kiln through the blower 500, and the reaction temperature is controlled by the joint control of the ventilation speed and the detection temperature in the kiln, and the reaction temperature is strictly controlled at 530-570°C, so that As 2 S 3 Reacts with oxygen and fully converts to As 2 o 3 and SO 2 Gas; before sending the high-temperature furnace gas produced by the rotary kiln into the first flue gas filter 200, first inject inert preheating gas into the first flue gas filter 200 through the blowback device 213 to filter the first flue gas The sintered inorganic porous material filter element in the device 200 is preheated to about 200°C, and then the high-temperature dust-containing furnace ga...

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Abstract

The invention discloses a treatment method for phosphoric acid arsenic-removed slag, which can effectively separate and recycle arsenic and other valued metal of the phosphoric acid arsenic-removed slag. The method comprises the following steps: 1) adding the phosphoric acid arsenic-removed slag into an industrial kiln and feeding oxygen-containing gas to perform oxidizing roasting, wherein the reaction temperature is controlled to be 530 to 570 DEG C; 2) conveying high-temperature dust-containing kiln gas which contains As2O3 and SO2 and is generated in the reaction process, into a first flue gas filter, and collecting arsenic-removed valued metal-enriched dust, wherein the first flue gas filter adopts a high-temperature sintering resistant inorganic porous material filter element and the dust content of the kiln gas purified by the first flue gas filter is below 10 to 20 mg / m<3>; 3) conveying the kiln gas purified by the first flue gas filter into a dividing wall type heat exchanger to enable the temperature of the kiln gas to be reduced to be below 150 DEG C; and 4) conveying the kiln gas at the outlet of the dividing wall type heat exchanger into a second flue gas filter, and collecting As2O3-enriched dust, wherein the dust content of the kiln gas purified by the second flue gas filter is below 10 to 20 mg / m<3>.

Description

technical field [0001] The invention relates to a treatment method for phosphoric acid arsenic removal slag. Background technique [0002] There are two types of industrial production methods of phosphoric acid, one is thermal production, and the product is thermal phosphoric acid; the other is wet production, and the product is wet phosphoric acid. Both hot-process phosphoric acid and wet-process phosphoric acid contain a considerable amount of arsenic. The existence of these arsenic is very harmful to the application of phosphoric acid, so arsenic removal treatment is required. Sulfide precipitation and arsenic removal is currently the most commonly used method for phosphoric acid removal of arsenic. Specifically, phosphoric acid is transported to the arsenic removal tower, and then P is added to the arsenic removal tower. 2 S 5 Arsenic removal agent, P 2 S 5 First react with water in phosphoric acid to generate H 2 S body and H 3 AsO 4 react to form a more stable A...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G28/00C01B17/52
Inventor 高麟汪涛樊彬
Owner CHENGDU INTERMENT TECH
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