阅读说明：本技术 一种废硝酸汞试剂回收方法 (Method for recovering waste mercury nitrate reagent ) 是由 李宝磊 祁国恕 侯海盟 赵岩 孔德勇 曾乐 闫向阳 于 2020-05-08 设计创作，主要内容包括：本发明公开了一种含汞废物回收行业中废硝酸汞试剂的回收方法,该方法是将硝酸汞加入大量水溶解后生成碱式盐沉淀,将其均匀缓慢加热分解,生成氧化汞,并对氧化汞进行火法回收单质汞的过程。同时对产生的含汞废气进行冷凝、吸附处理达标排放和对废水进行沉淀处理达标排放。该方法操作简单、处理成本较低,汞回收率平均达到97%以上,与固化填埋方法相比,具有工艺简单、成本低、经济性好等优点。(The invention discloses a method for recovering a waste mercuric nitrate reagent in the mercury-containing waste recovery industry. Meanwhile, the produced mercury-containing waste gas is condensed and adsorbed to achieve the emission standard and the waste water is precipitated to achieve the emission standard. The method has the advantages of simple operation, low treatment cost, mercury recovery rate of more than 97% on average, simple process, low cost, good economy and the like compared with a solidification landfill method.)

1. A method for recovering a waste mercury nitrate reagent is characterized by comprising the following steps: the method comprises the following steps:

step (I): adding the waste mercuric nitrate reagent into a reaction kettle, adding excessive distilled water, fully stirring and dissolving to generate basic nitrate Hg (NO)₃)₂The precipitate is formed by the precipitation of the mixture,

step (II): hg (NO) to be generated₃)₂Uniformly and slowly heating the precipitate to gradually decompose the precipitate and generate HgO;

step (three): and carrying out pyrogenic distillation and condensation on the generated HgO to obtain crude mercury, and purifying to obtain a simple substance mercury product.

2. The method for recovering the waste mercury nitrate reagent according to claim 1, characterized in that: the addition amount of the distilled water is 1-3L/kg Hg (NO)₃)₂The optimum range is 2-3L/kg Hg (NO)₃)₂。

3. The method for recovering the waste mercury nitrate reagent according to claim 1, characterized in that: the heating temperature is 50-100 ℃, and the optimal range is 70-100 ℃.

4. The method for recovering the waste mercury nitrate reagent according to claim 1, characterized in that: the reaction time is 3-5 h, and the optimal range is more than 4 h.

Technical Field

The invention belongs to the technical field of mercury wet regeneration, and particularly relates to a method for recovering a waste mercury nitrate reagent.

Background

In recent years, the national emphasis on the prevention and control of heavy metal pollution is increasing, and people pay more and more attention to the prevention and control of mercury pollution due to the effective notice of 'water guarantee about mercury' issued by the country in 8 months in 2017, and the pressure on the prevention and control of mercury pollution in the mercury-related industry is increasing. Particularly, the mercury smelting industry is strictly regulated by related national departments, and the industry faces huge environmental protection pressure.

At present, the waste mercury-containing reagent is treated by adopting a curing and burying technology in China, and the technology mainly has the problems of large consumption of a curing stabilizer, no resource recovery and the like.

In recent years, most of the domestic and foreign treatment and disposal of mercury-containing reagents are solidification landfill technologies, such as "a mercury-containing reagent waste stabilization and solidification disposal process" (application publication No. CN 108687114 a). The technology has a certain curing and stabilizing effect on the treatment of the waste mercury-containing reagent, is suitable for the treatment and disposal of various waste mercury-containing reagents, but has the problems of complex process, high treatment cost, certain landfill cost needing to be paid and the like, and is difficult to meet the actual requirements of waste production units.

The method has good application value in recovering metallic mercury from waste mercury nitrate reagent by wet extraction technology, generates basic salt precipitate after being dissolved by a large amount of water, generates mercury oxide by uniform and slow heating decomposition, recovers elemental mercury by pyrogenic process of the mercury oxide, and has the mercury recovery rate of more than 97%.

Disclosure of Invention

The invention mainly solves the technical problem of providing a method for recovering a waste mercury nitrate reagent, and solves the problems of difficult disposal and high cost of the current waste mercury-containing reagent.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a method for recovering a waste mercury nitrate reagent is technically characterized by comprising the following steps: the method comprises the following steps:

step (I): adding the waste mercuric nitrate reagent into a reaction kettle, adding excessive distilled water, fully stirring and dissolving to generate basic nitrate Hg (NO)₃)₂The precipitate is formed by the precipitation of the mixture,

step (II): hg (NO) to be generated₃)₂Uniformly and slowly heating the precipitate to gradually decompose the precipitate and generate HgO;

step (three): and carrying out pyrogenic distillation and condensation on the generated HgO to obtain crude mercury, and purifying to obtain a simple substance mercury product.

The adding amount of the distilled water in the invention is 1-3L/kg Hg (NO)₃)₂The optimum range is 2-3L/kg Hg (NO)₃)₂。

The reaction temperature in the invention is 50-100 ℃, and the optimal range is 70-100 ℃.

The reaction time is 2-5 h, and the optimal range is more than 4 h.

The invention has the advantages and beneficial effects that: the method has the advantages of simple operation, low treatment cost, average mercury recovery rate of more than 97 percent, simple process, low cost, good economy and the like compared with a solidification landfill method.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

As shown in figure 1, the invention relates to a method for recovering a waste mercury nitrate reagent, which comprises the steps of adding the waste mercury nitrate reagent into a reaction kettle, adding excessive distilled water, fully stirring and dissolving to generate basic nitrate Hg (NO)₃)₂Precipitating, uniformly and slowly heating the mercury to gradually decompose the mercury and generate HgO, then carrying out pyrogenic distillation and condensation on the HgO to obtain crude mercury, and purifying to obtain a simple substance mercury product. Meanwhile, the produced mercury-containing waste gas is condensed and adsorbed to achieve the emission standard and the waste water is precipitated to achieve the emission standard. The chemical reaction formula of the method is as follows:

the process flow is as follows: the waste mercury nitrate is added with excessive distilled water to be stirred and dissolved to generate Hg (NO)₃)₂Precipitating and filtering to obtain Hg (NO)₃)₂The filtered waste water entersPerforming precipitation treatment and then discharging after reaching the standard; for Hg (NO)₃)₂And uniformly and slowly heating to generate HgO, carrying out pyrogenic distillation and condensation to obtain elemental mercury, and treating the condensed waste gas by an adsorption device to reach the standard and discharge.

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.