阅读说明：本技术 一种天然球形石墨化学提纯及废水处理工艺 (Chemical purification and wastewater treatment process for natural spherical graphite ) 是由 陈新江 仇鹏举 赵一清 于 2021-09-03 设计创作，主要内容包括：本发明公开了一种天然球形石墨化学提纯及废水处理工艺,包括以下步骤：得到一次混酸溶液；取天然球形石墨与水加入反应釜内,继续搅拌至完全混合；将反应釜加热；送至压滤脱水机进行一次脱酸后洗涤至中性；得到二次混酸溶液；进行二次脱酸后洗涤至中性,进行脱水,烘干后得到高纯度球形石墨；得到的废水护送至废水处理系统进行回收处理,本发明涉及球形石墨提纯技术领域,本发明工艺流程紧凑,提纯效率高,整体流程成本低,适于量化生产,提纯过程中产生的废水可通过氨水进行中和沉淀后,再加入絮凝剂,将残余离子进一步反应沉淀,过滤后达到排放标准,整体废水处理速度较快,处理效果较佳,给人们的使用带来了方便。(The invention discloses a chemical purification and wastewater treatment process for natural spherical graphite, which comprises the following steps: obtaining a primary mixed acid solution; adding natural spherical graphite and water into a reaction kettle, and continuously stirring until the natural spherical graphite and the water are completely mixed; heating the reaction kettle; sending to a filter pressing dehydrator for primary deacidification and washing to be neutral; obtaining a secondary mixed acid solution; washing to neutrality after secondary deacidification, dehydrating, and drying to obtain high-purity spherical graphite; the obtained wastewater is delivered to a wastewater treatment system for recovery treatment, the invention relates to the technical field of spherical graphite purification, the process flow is compact, the purification efficiency is high, the cost of the whole flow is low, the process is suitable for quantitative production, wastewater generated in the purification process can be neutralized and precipitated by ammonia water, then a flocculating agent is added, residual ions are further reacted and precipitated, the discharge standard is reached after filtration, the whole wastewater treatment speed is high, the treatment effect is good, and convenience is brought to the use of people.)

1. A chemical purification process of natural spherical graphite is characterized by comprising the following steps:

s1, fully stirring and mixing hydrofluoric acid, hydrochloric acid and nitric acid to obtain a primary mixed acid solution;

s2, adding natural spherical graphite and water into the reaction kettle, mixing and stirring to form slurry, adding the mixed acid solution prepared in the step S1, and continuously stirring until the natural spherical graphite and the water are completely mixed;

s3, heating the reaction kettle to 80-100 ℃, and reacting for 10-14 h to obtain a primary reactant;

s4, conveying the primary reactant to a filter-pressing dehydrator, performing primary deacidification, washing to be neutral, and performing filter pressing to obtain a filter cake, wherein the pH value of washing water is 7;

s5, taking silicofluoric acid and nitric acid, and fully stirring and mixing to obtain a secondary mixed acid solution;

s6, mixing the filter cake with water, adding a secondary mixed acid solution, fully stirring and mixing, heating to 80-100 ℃, and reacting for 6-8 hours to obtain a secondary reactant;

s7, conveying the secondary reactant to a filter-pressing dehydrator, performing secondary deacidification, washing to be neutral, adjusting the pH of washing water to 7, dehydrating, and drying to obtain high-purity spherical graphite;

and S8, performing primary deacidification, secondary deacidification and dehydration to obtain wastewater, and conveying the wastewater to a wastewater treatment system for recovery treatment.

2. The chemical purification process of natural spherical graphite according to claim 1, wherein the mass ratio of hydrofluoric acid, hydrochloric acid, nitric acid, spherical graphite and water in step S2 is (15-25): (20-40): (10-15): 100: (80-120).

3. The chemical purification process of natural spherical graphite according to claim 1, wherein the mass ratio of the filter cake to the water in step S6 is 100: (50-80).

4. The chemical purification process of natural spherical graphite according to claim 1, wherein the water in step S2 and step S6 is ultrafiltration water.

5. The chemical purification process of natural spherical graphite according to claim 1, wherein the heating manner in steps S3 and S6 is natural gas heating.

6. A process for treating wastewater generated in the purification process of natural spherical graphite according to any one of claims 1 to 5, which comprises the following steps:

s1, conveying the wastewater to a sedimentation tank, introducing ammonia water with the concentration of 15 wt% -20 wt% into the sedimentation tank, measuring the pH value of the wastewater, stopping introducing the ammonia water when the pH value is more than 7, and standing for sedimentation;

s2, adding a flocculating agent into the wastewater subjected to precipitation in the step S1, reacting, and standing for precipitation;

s3, introducing the wastewater treated in the step S2 into a treatment tank, adding a water purification compound, mixing and stirring, and adjusting the pH value to 6-7;

and S4, passing the wastewater treated in the step S3 through a precision filter and an ultrafilter in sequence, and then reaching the discharge standard.

7. The process of claim 6, wherein the water purifying compound is aluminum trichloride.

8. The process for treating wastewater from chemical purification of natural spherical graphite according to claim 6, wherein the stirring time of step S3 is 30-50 min, and the stirring speed is 150 r/min.

Technical Field

The invention relates to the technical field of graphite purification, in particular to a process for chemically purifying natural spherical graphite and treating wastewater.

Background

Graphite is a crystalline carbon. Hexagonal system, iron black to dark gray. Density 2.25 g/cm 3, hardness 1.5, melting point 3652 deg.c and boiling point 4827 deg.c. The natural spherical graphite is soft, has a greasy feeling and can conduct electricity, wherein the natural spherical graphite is subjected to spheroidization by mainly using a mechanical force method, and graphite particles are subjected to plastic deformation and particle adsorption through a series of acting forces such as collision, friction, shearing and the like generated by mechanical action to obtain a finished spherical graphite product.

The existing spherical graphite purification technology has poor purification efficiency and higher cost, and can generate a large amount of wastewater in the purification process, and the wastewater is directly discharged to pollute the environment, thereby bringing inconvenience to people.

Disclosure of Invention

The invention aims to provide a process for chemically purifying natural spherical graphite and treating wastewater, and mainly aims to solve the problems that the existing purification technology is high in cost and low in efficiency, and the generated wastewater pollutes the environment.

The technical scheme of the invention is that the chemical purification process of the natural spherical graphite comprises the following steps:

s1, fully stirring and mixing hydrofluoric acid, hydrochloric acid and nitric acid to obtain a primary mixed acid solution;

s2, adding natural spherical graphite and water into the reaction kettle, mixing and stirring to form slurry, adding the mixed acid solution prepared in the step S1, and continuously stirring until the natural spherical graphite and the water are completely mixed;

s3, heating the reaction kettle to 80-100 ℃, and reacting for 10-14 h to obtain a primary reactant;

s4, conveying the primary reactant to a filter-pressing dehydrator, performing primary deacidification, washing to be neutral, and performing filter pressing to obtain a filter cake, wherein the pH value of washing water is 7;

s5, taking silicofluoric acid and nitric acid, and fully stirring and mixing to obtain a secondary mixed acid solution;

s6, mixing the filter cake with water, adding a secondary mixed acid solution, fully stirring and mixing, heating to 80-100 ℃, and reacting for 6-8 hours to obtain a secondary reactant;

s7, conveying the secondary reactant to a filter-pressing dehydrator, performing secondary deacidification, washing to be neutral, adjusting the pH of washing water to 7, dehydrating, and drying to obtain high-purity spherical graphite;

and S8, performing primary deacidification, secondary deacidification and dehydration to obtain wastewater, and conveying the wastewater to a wastewater treatment system for recovery treatment.

Preferably, in the step S2, the mass ratio of the hydrofluoric acid, the hydrochloric acid, the nitric acid, the spherical graphite and the water is (15-25): (20-40): (10-15): 100: (80-120).

Preferably, the mass ratio of the filter cake to the water in the step S6 is 100: (50-80).

Preferably, the water in step S2 and step S6 is ultrafiltration water.

Preferably, the heating method in steps S3 and S6 is natural gas heating.

A chemical purification wastewater treatment process for natural spherical graphite is used for treating wastewater generated by the spherical graphite purification process, and comprises the following steps:

s1, conveying the wastewater to a sedimentation tank, introducing ammonia water with the concentration of 15 wt% -20 wt% into the sedimentation tank, measuring the pH value of the wastewater, stopping introducing the ammonia water when the pH value is more than 7, and standing for sedimentation;

s2, adding a flocculating agent into the wastewater subjected to precipitation in the step S1, reacting, and standing for precipitation;

s3, introducing the wastewater treated in the step S2 into a treatment tank, adding a water purification compound, mixing and stirring, and adjusting the pH value to 6-7;

and S4, passing the wastewater treated in the step S3 through a precision filter and an ultrafilter in sequence, and then reaching the discharge standard.

Preferably, the water purifying compound is aluminum trichloride.

Preferably, the stirring time of the step S3 is 30-50 min, and the stirring speed is 150 r/min.

The invention has the beneficial effects that: the method has the advantages of compact process flow, high purification efficiency, low cost of the whole process flow and suitability for quantitative production, can quickly dissolve impurities in the spherical graphite by mixing hydrofluoric acid, hydrochloric acid, silicofluoric acid, nitric acid and the like to form a mixed acid solution, can neutralize and precipitate the waste water generated in the purification process by ammonia water, then adds a flocculating agent to further react and precipitate residual ions, neutralizes redundant hydrogen ions or hydroxide ions in the waste water by aluminum trichloride, achieves the discharge standard after filtration, has higher treatment speed of the whole waste water, better treatment effect and brings convenience to people.

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1: a chemical purification process of natural spherical graphite comprises the following steps:

s1, fully stirring and mixing hydrofluoric acid, hydrochloric acid and nitric acid to obtain a primary mixed acid solution;

s2, adding natural spherical graphite and water into a reaction kettle, mixing and stirring to form slurry, adding the mixed acid solution prepared in the step S1, and continuously stirring until the mixed acid solution is completely mixed, wherein the mass ratio of hydrofluoric acid, hydrochloric acid, nitric acid, spherical graphite to water is 15: 20: 10: 100: 80;

s3, heating the reaction kettle to 80 ℃, and reacting for 10 hours to obtain a primary reactant;

s4, conveying the primary reactant to a filter-pressing dehydrator, performing primary deacidification, washing to be neutral, and performing filter pressing to obtain a filter cake, wherein the pH value of washing water is 7;

s5, taking silicofluoric acid and nitric acid, and fully stirring and mixing to obtain a secondary mixed acid solution;

s6, mixing the filter cake with water, wherein the mass ratio of the filter cake to the water is 100: 50, adding the secondary mixed acid solution, fully stirring and mixing, heating to 80 ℃, and reacting for 6 hours to obtain a secondary reactant;

s7, conveying the secondary reactant to a filter-pressing dehydrator, performing secondary deacidification, washing to be neutral, adjusting the pH of washing water to 7, dehydrating, and drying to obtain high-purity spherical graphite;

and S8, performing primary deacidification, secondary deacidification and dehydration to obtain wastewater, and conveying the wastewater to a wastewater treatment system for recovery treatment.

A chemical purification wastewater treatment process for natural spherical graphite is used for treating wastewater generated by the spherical graphite purification process, and comprises the following steps:

s1, conveying the wastewater to a sedimentation tank, introducing ammonia water with the concentration of 15 wt% into the sedimentation tank, measuring the pH value of the wastewater, stopping introducing the ammonia water when the pH value is more than 7, and standing for sedimentation;

s2, adding a flocculating agent into the wastewater subjected to precipitation in the step S1, reacting, and standing for precipitation;

s3, introducing the wastewater treated in the step S2 into a treatment tank, adding a water purification compound, wherein the water purification compound is aluminum trichloride, mixing and stirring, adjusting the pH value to 6, stirring for 30min, and stirring at a speed of 150 r/min;

and S4, passing the wastewater treated in the step S3 through a precision filter and an ultrafilter in sequence, and then reaching the discharge standard.

Example 2: a chemical purification process of natural spherical graphite comprises the following steps:

s1, fully stirring and mixing hydrofluoric acid, hydrochloric acid and nitric acid to obtain a primary mixed acid solution;

s2, adding natural spherical graphite and water into a reaction kettle, mixing and stirring to form slurry, adding the mixed acid solution prepared in the step S1, and continuously stirring until the mixed acid solution is completely mixed, wherein the mass ratio of hydrofluoric acid, hydrochloric acid, nitric acid, spherical graphite to water is 20: 30: 13: 100: 100, respectively;

s3, heating the reaction kettle to 90 ℃, and reacting for 12h to obtain a primary reactant;

s4, conveying the primary reactant to a filter-pressing dehydrator, performing primary deacidification, washing to be neutral, and performing filter pressing to obtain a filter cake, wherein the pH value of washing water is 7;

s5, taking silicofluoric acid and nitric acid, and fully stirring and mixing to obtain a secondary mixed acid solution;

s6, mixing the filter cake with water, wherein the mass ratio of the filter cake to the water is 100: 70, adding the secondary mixed acid solution, fully stirring and mixing, heating to 90 ℃, and reacting for 7 hours to obtain a secondary reactant;

s7, conveying the secondary reactant to a filter-pressing dehydrator, performing secondary deacidification, washing to be neutral, adjusting the pH of washing water to 7, dehydrating, and drying to obtain high-purity spherical graphite;

and S8, performing primary deacidification, secondary deacidification and dehydration to obtain wastewater, and conveying the wastewater to a wastewater treatment system for recovery treatment.

A chemical purification wastewater treatment process for natural spherical graphite is used for treating wastewater generated by the spherical graphite purification process, and comprises the following steps:

s1, conveying the wastewater to a sedimentation tank, introducing ammonia water with the concentration of 18 wt% into the sedimentation tank, measuring the pH value of the wastewater, stopping introducing the ammonia water when the pH value is more than 7, and standing for sedimentation;

s2, adding a flocculating agent into the wastewater subjected to precipitation in the step S1, reacting, and standing for precipitation;

s3, introducing the wastewater treated in the step S2 into a treatment tank, adding a water purification compound, wherein the water purification compound is aluminum trichloride, mixing and stirring, adjusting the pH value to 7, and stirring for 40min at a stirring speed of 150 r/min;

and S4, passing the wastewater treated in the step S3 through a precision filter and an ultrafilter in sequence, and then reaching the discharge standard.

Example 3: a chemical purification process of natural spherical graphite comprises the following steps:

s1, fully stirring and mixing hydrofluoric acid, hydrochloric acid and nitric acid to obtain a primary mixed acid solution;

s2, adding natural spherical graphite and water into a reaction kettle, mixing and stirring to form slurry, adding the mixed acid solution prepared in the step S1, and continuously stirring until the mixed acid solution is completely mixed, wherein the mass ratio of hydrofluoric acid, hydrochloric acid, nitric acid, spherical graphite to water is 25: 40: 15: 100: 120 of a solvent;

s3, heating the reaction kettle to 100 ℃, and reacting for 14h to obtain a primary reactant;

s4, conveying the primary reactant to a filter-pressing dehydrator, performing primary deacidification, washing to be neutral, and performing filter pressing to obtain a filter cake, wherein the pH value of washing water is 7;

s5, taking silicofluoric acid and nitric acid, and fully stirring and mixing to obtain a secondary mixed acid solution;

s6, mixing the filter cake with water, wherein the mass ratio of the filter cake to the water is 100: 80, adding the secondary mixed acid solution, fully stirring and mixing, heating to 100 ℃, and reacting for 8 hours to obtain a secondary reactant;

s7, conveying the secondary reactant to a filter-pressing dehydrator, performing secondary deacidification, washing to be neutral, adjusting the pH of washing water to 7, dehydrating, and drying to obtain high-purity spherical graphite;

and S8, performing primary deacidification, secondary deacidification and dehydration to obtain wastewater, and conveying the wastewater to a wastewater treatment system for recovery treatment.

A chemical purification wastewater treatment process for natural spherical graphite is used for treating wastewater generated by the spherical graphite purification process, and comprises the following steps:

s1, conveying the wastewater to a sedimentation tank, introducing ammonia water with the concentration of 20 wt% into the sedimentation tank, measuring the pH value of the wastewater, stopping introducing the ammonia water when the pH value is more than 7, and standing for sedimentation;

s2, adding a flocculating agent into the wastewater subjected to precipitation in the step S1, reacting, and standing for precipitation;

s3, introducing the wastewater treated in the step S2 into a treatment tank, adding a water purification compound, wherein the water purification compound is aluminum trichloride, mixing and stirring, adjusting the pH value to 7, and stirring for 50min at a stirring speed of 150 r/min;

and S4, passing the wastewater treated in the step S3 through a precision filter and an ultrafilter in sequence, and then reaching the discharge standard.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.