阅读说明：本技术 一种铅废料循环脱硫的方法 (Method for circularly desulfurizing lead waste ) 是由 代少振 项晨 于 2020-10-09 设计创作，主要内容包括：本发明涉及一种铅废料循环脱硫的方法,其特征在于,包括如下步骤：步骤1：铅废料与碳酸氢钠反应脱硫；步骤2,固液分离后,得到碳酸铅与脱硫母液；步骤3,脱硫母液加入碳酸钙反应,得到碳酸氢钙和硫酸钙；步骤4,所述步骤3得到的碳酸氢钙返回步骤1继续脱硫。本发明的铅废料循环脱硫的方法可循环利用、效率高、能耗低。(The invention relates to a method for circularly desulfurizing lead waste, which is characterized by comprising the following steps of: step 1: reacting the lead waste with sodium bicarbonate for desulfurization; step 2, after solid-liquid separation, obtaining lead carbonate and desulfurization mother liquor; step 3, adding calcium carbonate into the desulfurization mother liquor to react to obtain calcium bicarbonate and calcium sulfate; and 4, returning the calcium bicarbonate obtained in the step 3 to the step 1 to continue desulfurization. The method for circularly desulfurizing the lead waste can be recycled, and has high efficiency and low energy consumption.)

1. The method for circularly desulfurizing the lead waste is characterized by comprising the following steps of: step 1: reacting the lead waste with sodium bicarbonate for desulfurization; step 2, after solid-liquid separation, obtaining lead carbonate and desulfurization mother liquor; step 3, adding calcium carbonate into the desulfurization mother liquor to react to obtain calcium bicarbonate and calcium sulfate; and 4, returning the calcium bicarbonate obtained in the step 3 to the step 1 to continue desulfurization.

2. The method for recycling desulfurization of lead waste material according to claim 1, wherein in the step 3, the desulfurization mother liquor is added with calcium carbonate for reaction, and simultaneously carbon dioxide gas generated in the step 1 is introduced.

3. The method for the recycling desulfurization of lead waste materials as claimed in claim 1 or 2, wherein in the step 1, the molar mass ratio of the waste lead plaster to the sodium bicarbonate is 1:2 to 1: 5, putting the mixture into a ball-milling reaction tank, and then adding a mixture of the lead paste and the lead paste in a mass ratio of 2: 1 to 5: 1, mixing and grinding the mixture at 10-100 ℃ for 10-30min, and desulfurizing.

4. The method for recycling desulfurization of lead waste material according to claim 1 or 2, characterized in that in the step 3, a desulfurization mother liquor is added with a molar mass ratio of sulfate radical to 1: 1 to 2: 1 calcium carbonate, and introducing carbon dioxide gas generated in the step 1 at the temperature of 10-60 ℃ while stirring.

Technical Field

The invention relates to the technical field of waste treatment.

Background

The process comprises the steps of putting the lead plaster and alkali liquor into a ball mill according to a ratio to react, and filtering to obtain treated lead plaster and filtrate, wherein the filtrate contains sodium sulfate, sodium hydroxide and water. At present, the way of processing the filtrate on the experimental line is a cooling crystallization way, sodium sulfate forms crystals in the form of Na2SO4 & 10H2O under a low-temperature environment, the sodium sulfate is left by a centrifuge, and the filtrate is recycled. The low-temperature crystallization mode has high energy consumption and long processing time, and the product sodium sulfate obtained by the low-temperature crystallization mode is not well removed. CN201810778845.1 discloses a recycling method of a lead plaster desulphurization solution, which is characterized in that sodium hydroxide alkali liquor and waste lead plaster are used for desulphurization according to a certain proportion, the desulphurization solution is causticized by calcium oxide to convert sodium sulfate in the desulphurization solution into sodium hydroxide for recycling, calcium sulfate is prepared into calcium oxide for recycling after high-temperature roasting, and sulfur dioxide is prepared into 1.1g/ml dilute sulfuric acid. The method has the defects that the conversion efficiency of preparing sodium hydroxide by causticizing sodium sulfate with calcium oxide is lower than 80 percent, and the economy and the environmental protection of preparing calcium oxide and sulfur dioxide by calcining calcium sulfate at high temperature are lower.

Disclosure of Invention

In order to solve the technical problem, the invention provides a method for circularly desulfurizing lead waste, which is characterized by comprising the following steps of: step 1: reacting the lead waste with sodium bicarbonate for desulfurization; step 2, after solid-liquid separation, obtaining lead carbonate and desulfurization mother liquor; step 3, adding calcium carbonate into the desulfurization mother liquor to react to obtain calcium bicarbonate and calcium sulfate; and 4, returning the calcium bicarbonate obtained in the step 3 to the step 1 to continue desulfurization.

Further, in the step 3, calcium carbonate is added into the desulfurization mother liquor for reaction, and carbon dioxide gas generated in the step 1 is introduced at the same time.

Further, in the step 1, the molar mass ratio of the waste lead plaster to the sodium bicarbonate is 1:2 to 1: 5, putting the mixture into a ball-milling reaction tank, and then adding a mixture of the lead paste and the lead paste in a mass ratio of 2: 1 to 5: 1, mixing and grinding the mixture at 10-100 ℃ for 10-30min, and desulfurizing.

Further, in the step 3, adding a catalyst in a molar mass ratio of 1: 1 to 2: 1 calcium carbonate, and introducing carbon dioxide gas generated in the step 1 at the temperature of 10-60 ℃ while stirring.

The method for circularly desulfurizing the lead waste can be recycled, and has high efficiency and low energy consumption.

Drawings

FIG. 1 is a flow chart of the recycling desulfurization of lead scrap according to the present invention.

Detailed Description

The invention is further described below with reference to the specific drawings.

As shown in fig. 1, the method for recycling and desulfurizing lead scrap of the present invention comprises the following steps:

step 1, reacting waste lead plaster or lead-containing waste with sodium bicarbonate for desulfurization

Putting waste lead plaster (according to the amount of lead sulfate in the lead plaster) and sodium bicarbonate into a ball-milling reaction tank according to a molar mass ratio (1:2-5), then adding pure water according to the mass ratio (2-5: 1) to the lead plaster, mixing and grinding for 10-30min at 10-100 ℃, wherein the lead sulfate conversion efficiency is more than 99.5%, transferring the mixed slurry into a buffer tank for standby after the grinding reaction is finished, and collecting carbon dioxide generated in the reaction process for standby.

The desulfurization process occurs as follows.

The reaction equation is as follows: PBSO4+2NaHCO3 → PbCO3+ Na2SO4+ H2O + CO2

Step 2, solid-liquid separation of the mixed slurry

And performing filter pressing solid-liquid separation on the mixed slurry in the buffer tank, washing and replacing the lead plaster in the filter cake by using pure water of about 10 percent to remove sodium sulfate in the lead plaster and the desulfurization mother liquor, and sending the sodium sulfate and the desulfurization mother liquor to a circulating regeneration reaction kettle to perform mother liquor circulating regeneration.

Step 3, regenerating sodium bicarbonate mother liquor

Conveying the desulfurization mother liquor and the washing liquid to a reaction kettle, and adding a mixture of the desulfurization mother liquor and the washing liquid, wherein the molar mass ratio of the desulfurization mother liquor to sulfate radical is 1-2: 1, introducing collected carbon dioxide gas at the temperature of 10-60 ℃ while stirring. Reacting for 0.5-3 h to obtain sodium bicarbonate and calcium sulfate, and performing solid-liquid separation to obtain sodium bicarbonate for circular desulfurization and selling of calcium sulfate.

The reaction equation is as follows:

Na2SO4+CaCO3+CO2+H2O→2NaHCO3+CaSO4↓

and 4, returning the calcium bicarbonate obtained in the step 3 to the step 1 to continue desulfurization.

The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.