Process for recycling iron/steel acid-washing waste hydrochloric acid through evaporation burning and coupling process

A technology of iron and steel pickling waste and waste hydrochloric acid, which is applied in the direction of chlorine/hydrogen chloride, etc., can solve the problems of large investment, large floor space, and high energy consumption, and achieve the effects of low operating costs, energy saving, and reduced energy consumption

Inactive Publication Date: 2010-07-28
BEIJING TIANTAIXING ENG TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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However, there are also disadvantages such as large ...

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  • Process for recycling iron/steel acid-washing waste hydrochloric acid through evaporation burning and coupling process

Examples

Experimental program
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Effect test

example 1

[0028] Example 1 uses evaporation-incineration coupling process to recover waste iron and steel acid.

[0029] The waste acid from the steel pickling waste hydrochloric acid storage tank is pumped to the evaporator for heating and vaporization. The vapor-liquid mixture is vaporized, flashed and separated in a high-efficiency anti-corrosion vaporizer, so that 70% of the water and hydrochloric acid in the waste acid are evaporated, and the liquid phase is greatly concentrated to make the specific gravity reach 1.6g / cm3. The vapor phase is sent to the condenser to be condensed to recover dilute hydrochloric acid, and sent to the dilute acid storage tank. The ferrous chloride-containing concentrated liquid separated from the high-efficiency anti-corrosion evaporator is sent to the evaporation crystallizer for deep evaporation, concentration, cooling, and crystal nucleus formation. The evaporated hydrochloric acid vapor is condensed through the condenser to recover dilute hydrochl...

example 2

[0032] Example 2 uses evaporation-incineration coupling process to recover waste iron and steel acid.

[0033] The waste acid from the steel pickling waste hydrochloric acid storage tank is pumped to the evaporator for heating and vaporization. The vapor-liquid mixture is vaporized, flashed and separated in a high-efficiency anti-corrosion vaporizer, so that 60% of water and hydrochloric acid in the waste acid are evaporated, and the liquid specific gravity reaches 1.4g / cm3. The vapor phase is sent to the condenser to be condensed to recover dilute hydrochloric acid, and sent to the dilute acid storage tank. The ferrous chloride-containing concentrated liquid separated from the high-efficiency anti-corrosion evaporator is sent to the evaporation crystallizer for deep evaporation, concentration, cooling, and crystal nucleus formation. The evaporated hydrochloric acid vapor is condensed through the condenser to recover dilute hydrochloric acid, which is also sent to the dilute ...

example 3

[0036] Example 3 uses evaporation process to recycle waste hydrochloric acid containing oxalic acid in rare earth production.

[0037] The waste acid from the waste hydrochloric acid storage tank of the rare earth production line is pumped to the evaporator for heating and vaporization. The vapor-liquid mixture is vaporized, flashed and separated in a high-efficiency anti-corrosion vaporizer, so that 65% of water and hydrochloric acid in the waste acid are evaporated, and the specific gravity of the liquid reaches 1.5g / cm3. The vapor phase is sent to the condenser to be condensed to recover dilute hydrochloric acid, and sent to the dilute acid storage tank. The oxalic acid-containing concentrated liquid separated from the high-efficiency anti-corrosion vaporizer is sent to the cooling crystallizer for cooling and cooling to form crystal nuclei. Finally, it is sent to a crystallization filter for solid-liquid separation, and the obtained crystalline oxalic acid and a small amo...

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PUM

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Abstract

The invention discloses a process for recycling iron/steel acid-washing waste hydrochloric acid through an evaporation burning and coupling process, which belongs to the technology of iron/steel acid-washing waste hydrochloric acid recycling packaged process. In the process: first, 50-70 percent of water and free hydrochloric acid in the waste hydrochloric acid are vaporized and separated after being heated and evaporated, the vapor is separated from the waste hydrochloric acid, and the proportion of the waste acid reaches 1.4-1.6g/cm<3>; the dilute hydrochloric acid is obtained through vapor condensation; and the liquid phase adopts a thermal crystallization process, the evaporation temperature is controlled within 100-110 DEG C, azeotropic hydrochloric acid is obtained by evaporation from the concentrated waste hydrochloric acid for the second time, the ferrous chloride is uninterruptedly and continuously separated from the waste acid concentrated solution, and the ferrous chloride is crystallized; second, the obtained ferrous chloride is burnt under 800 DEG C to obtain ferric oxide powder and HCl gas; the gas is absorbed for stages by the dilute hydrochloric acid obtained by adopting the evaporation process and the thermal crystallization process, and finally, the hydrochloric acid with different concentrations can be obtained to directly return to the acid-washing line for reuse. The invention recycles and reuses the acid-washing waste acid through the process, thereby reducing the consumption of the iron/steel acid-washing waste hydrochloric acid, being beneficial for the environmental protection and realizing the purposes of recycling and reusing the waste hydrochloric acid.

Description

technical field [0001] The invention belongs to a complete set of technology for recycling waste acid from iron and steel pickling. That is, the evaporation-incineration coupling process technology is used to recycle waste hydrochloric acid from steel pickling to obtain hydrochloric acid with the concentration required by the user, such as 20% hydrochloric acid and iron oxide powder. At the same time, in the middle process, the ferrous chloride product can be obtained. Adopting the process to recycle waste pickling acid for reuse reduces the consumption of hydrochloric acid for steel pickling, is beneficial to environmental protection, and realizes the goal of recycling and recycling waste hydrochloric acid. Background technique [0002] At present, there are three main methods for the treatment of waste hydrochloric acid from iron and steel pickling: simple neutralization method, negative pressure evaporation process and direct incineration technology. In comparison, the ...

Claims

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Application Information

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IPC IPC(8): C01B7/01
Inventor 雍兴海雍兴跃赵明
Owner BEIJING TIANTAIXING ENG TECH
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