阅读说明：本技术 磷酸法活性炭生产中回收磷酸的高效纯化方法 (Efficient purification method for recovering phosphoric acid in phosphoric acid method activated carbon production ) 是由 周建斌 张书 马欢欢 王亮才 周建明 陈登宇 章一蒙 于 2020-06-10 设计创作，主要内容包括：本发明提出的是磷酸法活性炭生产中回收磷酸的高效纯化方法,包括如下步骤：1)称取福美钠置于高浓度酸水回收罐,放入高浓度回收磷酸后再放入一定量的硫酸,充分搅拌生成硫酸钙沉淀和有机络合物沉淀；2)静置后,将非底部磷酸溶液配制一定波美度的磷酸溶液,与木屑混合搅拌浸湿；3)对底部剩余物进行搅拌、过滤,再将过滤回收的磷酸溶液打磷酸梯度液中,用于洗涤回收。本发明利用硫酸与钙离子反应生成硫酸钙沉淀并释放氢离子、福美钠与各类重金属离子生成不溶性的螯合盐沉淀,硫酸可以有效促进磷酸渗透到木屑中,利于炭化和活化；该工艺操作简单,原料易得,易于工业化推广,生产成本较低,具有显著的经济效益。(The invention provides a high-efficiency purification method for recovering phosphoric acid in the production of phosphoric acid method activated carbon, which comprises the following steps: 1) weighing sodium ferbamate, putting the sodium ferbamate into a high-concentration acid water recovery tank, putting high-concentration recovered phosphoric acid, then putting a certain amount of sulfuric acid, and fully stirring to generate calcium sulfate precipitate and organic complex precipitate; 2) standing, preparing a phosphoric acid solution with a certain Baume degree from a non-bottom phosphoric acid solution, and mixing, stirring and soaking the non-bottom phosphoric acid solution and the wood chips; 3) stirring and filtering the bottom residues, and pumping the phosphoric acid solution recovered by filtering into a phosphoric acid gradient solution for washing and recovering. The sulfuric acid can effectively promote phosphoric acid to permeate into wood chips, and is beneficial to carbonization and activation; the process has the advantages of simple operation, easily obtained raw materials, easy industrial popularization, lower production cost and obvious economic benefit.)

1. The high-efficiency purification method for recovering phosphoric acid in the production of activated carbon by a phosphoric acid method is characterized by comprising the following steps of:

1) weighing sodium ferbamate, putting the sodium ferbamate into a high-concentration acid water recovery tank, putting the high-concentration recovered phosphoric acid washed and recovered by a phosphoric acid method activated carbon production process, then putting a certain amount of sulfuric acid, and fully stirring to generate calcium sulfate precipitate and organic complex precipitate;

2) standing, using the non-bottom upper layer phosphoric acid solution for preparing a phosphoric acid solution with a certain Baume degree, and mixing, stirring and soaking the prepared phosphoric acid solution with the certain Baume degree and the wood chips;

3) stirring and filtering the residue at the bottom of the high-concentration acid water recovery tank, and pumping the phosphoric acid solution recovered by filtering into a phosphoric acid gradient liquid in the production of the phosphoric acid method activated carbon for washing and recovering phosphoric acid in the production of the phosphoric acid method activated carbon.

2. The method for purifying phosphoric acid recovered from the production of activated carbon by phosphoric acid method according to claim 1, wherein the volume ratio of sodium ferulate to the recovered phosphoric acid is 1.8-2.2 kg/m³。

3. The efficient purification method for the recovered phosphoric acid in the production of the phosphoric acid method activated carbon according to claim 1, characterized in that the volume ratio of the sulfuric acid to the recovered phosphoric acid is 0.017-0.023.

4. The method for purifying phosphoric acid recovered from the production of activated carbon by phosphoric acid process according to claim 1, wherein the mass fraction of sulfuric acid is 98%.

5. The efficient purification method for the recovered phosphoric acid in the production of the phosphoric acid method activated carbon according to any one of claims 1 to 4, characterized in that the utilization rate of the recovered phosphoric acid is 88 to 92%.

Technical Field

The invention relates to a high-efficiency purification method for recovering phosphoric acid in the production of activated carbon by a phosphoric acid method, belonging to the field of activated carbon production processes in the chemical field.

Background

Phosphorus is widely applied to industries such as agriculture, biology, medicine, industry and the like, but a large amount of phosphorus is discharged along with wastewater, so that water eutrophication is caused, and the recovery and reutilization of phosphorus resources are particularly important. The recovery of the phosphorus resource not only reduces the discharge concentration of phosphorus in the wastewater, but also obtains the precious phosphorus resource again, thus being a better measure for realizing the win-win of economic benefit and environmental benefit.

Phosphoric acid is used as an activating agent in the production of activated carbon to promote infiltration, dehydration, hydrolysis, aromatization and the like, and has a cross-linking effect with saccharide molecules, activated carbon after being activated by an activating furnace contains a relatively high amount of phosphoric acid, the phosphoric acid needs to be washed and recycled, but the recycled phosphoric acid liquid contains heavy metal ions, and the recycled phosphoric acid liquid can increase the ash content of the finished activated carbon product and reduce the quality of the activated carbon product if the activated carbon is not treated (the activated carbon for food and medicine has special requirements, for example, the heavy metal content of the activated carbon for medicine is not more than thirty parts per million, and the burning residue of the activated carbon is not more than three percent), so the process steps are the keys of reducing the cost, controlling the ash content and reducing the emission of tail gas and waste water in the production of the activated carbon by a phosphoric acid.

Meanwhile, in the production of the activated carbon by the phosphoric acid method, another important process for determining the quality of the activated carbon is that phosphoric acid can better permeate into a wood chip structure, and if the phosphoric acid uniformly and fully permeates into wood chips, the quality of the activated carbon prepared by the processes of activation and the like is higher. In the phosphoric acid infiltration process in the production process of the activated carbon by the phosphoric acid method, a certain amount of phosphoric acid with a certain Baume degree is directly added into dried wood chips, and then the mixture is stirred and mixed and directly enters the processes of activation and the like, so that the phosphoric acid is not infiltrated into the wood chips deeply and uniformly, and the quality of the activated carbon cannot reach the best. In addition, although the method for recovering phosphorus by using a chemical precipitation method in the prior art is simple in process and can achieve higher recovery rate, at the present stage, activated carbon production enterprises adopting a phosphoric acid method mainly adopt calcium hydroxide to react with phosphate radical to form calcium phosphate precipitate, and then purify the recovered phosphoric acid through a precipitation separation process.

Disclosure of Invention

The invention aims to overcome the defects of the existing phosphoric acid method activated carbon production technology, provides an efficient purification method for recovering phosphoric acid in phosphoric acid method activated carbon production, integrally promotes a phosphoric acid recovery device system, reduces acid consumption, reduces production cost and reduces discharge.

The technical solution of the invention is as follows: the efficient purification method for recovering phosphoric acid in the production of activated carbon by a phosphoric acid method comprises the following steps:

1) weighing sodium ferulate, placing in a high-concentration acid water recovery tank, and placing in high-concentration recovered phosphoric acid obtained by washing and recovering with phosphoric acid method activated carbon production process, wherein the mass (kg) of sodium ferulate and the volume (m) of high-concentration recovered phosphoric acid³) The ratio is 1.8-2.2; adding a certain amount of sulfuric acid, wherein the mass fraction of the sulfuric acid is 98%, and the volume ratio of the sulfuric acid to the recovered phosphoric acid is 0.017-0.023; fully stirring to generate calcium sulfate precipitate and organic complex precipitate;

2) standing, using the non-bottom upper layer phosphoric acid solution for preparing a phosphoric acid solution with a certain Baume degree, and mixing, stirring and soaking the prepared phosphoric acid solution with the certain Baume degree and the wood chips;

3) stirring and filtering the residue at the bottom of the high-concentration acid water recovery tank, and pumping the phosphoric acid solution recovered by filtering into a phosphoric acid gradient liquid in the production of the phosphoric acid method activated carbon for washing and recovering phosphoric acid in the production of the phosphoric acid method activated carbon.

Compared with the prior art, the invention has the advantages that:

1) sulfuric acid reacts with calcium ions to generate calcium sulfate precipitates and release hydrogen ions, sodium ferulate and various heavy metal ions (such as: chromium, iron, copper, zinc) to form insoluble chelate salts and form precipitates;

2) the sulfuric acid can effectively promote phosphoric acid to permeate into wood chips, and is beneficial to carbonization and activation;

3) the method has the advantages of simple process operation, easily obtained raw materials, easy industrial popularization, lower production cost and obvious economic benefit.

Drawings

FIG. 1 is a schematic flow diagram of a high-efficiency purification method for recovering phosphoric acid in the production of activated carbon by a phosphoric acid method.

Detailed Description

The technical scheme of the invention is described in the following with the accompanying drawings of the specification. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The high-efficiency purification method for recovering phosphoric acid in the production of phosphoric acid method activated carbon shown in figure 1 specifically comprises the following steps:

1) weighing sodium ferbamate, putting the sodium ferbamate into a high-concentration acid water recovery tank, putting the high-concentration recovered phosphoric acid washed and recovered by a phosphoric acid method activated carbon production process, then putting a certain amount of sulfuric acid, and fully stirring to generate calcium sulfate precipitate and organic complex precipitate;

2) after standing, the non-bottom upper layer phosphoric acid solution is used for preparing a phosphoric acid solution with a certain Baume degree, the prepared phosphoric acid solution with the certain Baume degree is mixed, stirred and soaked with wood chips, and a small amount of unreacted sulfuric acid contained in the phosphoric acid can effectively promote the phosphoric acid to permeate into the wood chips, so that carbonization and activation are facilitated;

3) stirring and filtering the residue at the bottom of the high-concentration acid water recovery tank, and pumping the phosphoric acid solution recovered by filtering into a phosphoric acid gradient liquid in the production of the phosphoric acid method activated carbon for washing and recovering phosphoric acid in the production of the phosphoric acid method activated carbon.

Wherein the mass (kg) of sodium ferometalate and the volume (m) of recovered phosphoric acid³) The ratio is 1.8 to 2.2.

Wherein the volume ratio of the sulfuric acid to the recovered phosphoric acid is 0.017-0.023.

Wherein the mass fraction of the sulfuric acid is 98%.

Wherein the utilization rate of the recovered phosphoric acid is 88-92%.

The rest steps of the production process of the activated carbon adopting the method are carried out according to the existing flow of the activated carbon by the conventional phosphoric acid method.

The technical solution and the technical effects of the present invention are further described below according to the examples.