阅读说明：本技术 一种六价铬还原剂及其制备方法 (Hexavalent chromium reducing agent and preparation method thereof ) 是由 张祯 张宏川 张小川 于 2020-06-11 设计创作，主要内容包括：本发明公开了一种六价铬还原剂,包括：11-23重量份的亚铁离子,2-9重量份的亚锡离子,2-4份的杂醚化三聚氰胺树脂,1-2份的对氨基水杨酸钠,0.2-0.4份的纳米氧化铝,40-60重量份的溶剂,4-6重量份的分散剂,2-4重量份的稳定剂；所述溶剂为三乙醇胺、乙二胺、水,比例为2-4∶1-2∶6-8；稳定剂为木质素磺酸盐。(The invention discloses a hexavalent chromium reducing agent, which comprises the following components: 11-23 parts of ferrous ions, 2-9 parts of stannous ions, 2-4 parts of heteroetherified melamine resin, 1-2 parts of sodium para-aminosalicylate, 0.2-0.4 part of nano-alumina, 40-60 parts of solvent, 4-6 parts of dispersant and 2-4 parts of stabilizer; the solvent is triethanolamine, ethylenediamine and water in a ratio of 2-4: 1-2: 6-8; the stabilizer is lignosulfonate.)

1. A hexavalent chromium reducing agent, comprising: 11-23 parts of ferrous ions, 2-9 parts of stannous ions, 2-4 parts of heteroetherified melamine resin, 1-2 parts of sodium para-aminosalicylate, 0.2-0.4 part of nano-alumina, 40-60 parts of solvent, 4-6 parts of dispersant and 2-4 parts of stabilizer; the solvent is triethanolamine, ethylenediamine and water in a ratio of 2-4: 1-2: 6-8; the stabilizer is lignosulfonate.

2. The hexavalent chromium reducing agent of claim 1, comprising: 17 parts by weight of ferrous ions, 5.5 parts by weight of stannous ions, 3 parts by weight of heteroetherified melamine resin, 1.5 parts by weight of sodium para-aminosalicylate, 0.3 part by weight of nano-alumina, 50 parts by weight of solvent, 5 parts by weight of dispersant and 3 parts by weight of stabilizer; the solvent is triethanolamine, ethylenediamine and water in a ratio of 3: 1.5: 7.

3. The hexavalent chromium reducing agent of claim 1, wherein the stannous ions are derived from any one of stannous sulfate, stannous chloride, or a mixture of both.

4. The hexavalent chromium reducing agent of claim 1, wherein the ferrous ion is derived from any one of ferrous sulfate, ferrous chloride, or a mixture of both.

5. The hexavalent chromium reducing agent of claim 1, wherein the lignosulfonate is calcium lignosulfonate.

6. The hexavalent chromium reducing agent of claim 1, wherein the dispersant is any one of polyethylene glycol, triisopropanolamine, or a mixture of both; wherein the molecular weight of the polyethylene glycol is 200-400.

7. The hexavalent chromium reducing agent according to claim 1, wherein the heteroetherification melamine resin is prepared by adjusting the pH of an aqueous solution of formaldehyde to 10 to 11 with triethanolamine, then mixing melamine and the aqueous solution of formaldehyde in proportion, heating to 70 to 80 ℃, adding methanol and butanol to continue reacting for 2 to 4 hours after the color of the mixed solution gradually changes from white to clear and transparent, respectively to obtain the heteroetherification melamine resin; the molar ratio of the raw materials of melamine, formaldehyde, methanol and butanol in the hetereetherified melamine resin is 1: 5: 3.

8. A process for the preparation of the hexavalent chromium reducing agent according to any one of claims 1 to 7, comprising:

(1) uniformly mixing a solvent, ferrous ions, stannous ions and a stabilizer at the temperature of 20-40 ℃, and filtering by using a 200-mesh screen to obtain a first mixture;

(2) adding a dispersing agent into the first mixture, and uniformly mixing;

(3) and (3) uniformly mixing the heteroetherification melamine resin, the sodium p-aminosalicylate and the nano aluminum oxide, adding the mixture into the solution obtained in the step (2), uniformly mixing, and filtering by using a 200-mesh screen.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of building materials, and particularly relates to a hexavalent chromium reducing agent and a preparation method thereof.

[ background of the invention ]

The cement is an indispensable building material in national economic development and is also one of the artificial building materials with the largest yield in the world at present. Meanwhile, the per-capita consumption of cement is an important index for measuring whether the country is developed or not, and the cement plays an important role in the development and progress of human civilization. In view of the development of the current state of the art in the world, no building material has been able to replace cement for a short time.

Because the content of hexavalent chromium in the cement exceeds the standard and the harm is caused to human and environment, the treatment of the hexavalent chromium in the cement is imperative. Hexavalent chromium is 100 times more toxic than trivalent chromium, so control of Cr6+ in cement generally uses a chemical reductant method, i.e. reduction of soluble Cr (vi) to Cr (iii) with low toxicity. Since the durability of the existing reducing agents such as ferrous sulfate to reduce hexavalent chromium is a serious problem, it is very sensitive to humidity and temperature, and its reducing power is gradually lost after grinding and during the storage of cement. This requires the use of larger doses of ferrous sulphate, which is more expensive than desired. Cement is generally alkaline, a plurality of reducing agents can play a reducing role under an acidic condition, and the reducing effect is easily lost under an alkaline condition, so that the development of an efficient, cheap and stable reducing agent capable of effectively reducing the high-toxicity hexavalent chromium in the cement into the low-toxicity trivalent chromium for a long time is needed.

Chinese patent (CN106365479B) discloses a cement hexavalent chromium compound reducing agent, wherein the mass percentages of sodium sulfite 15-20%, ferrous sulfate 60-70%, manganese sulfate 10-20%, stannous sulfate 1-10%, and total amount 100% are all mass percentages, the provided cement hexavalent chromium compound reducing agent has good chemical stability, can reduce water-soluble hexavalent chromium into trivalent chromium, and the content of hexavalent chromium can be maintained at 2ppm level for 3 months, the fineness of cement can be reduced by adding the reducing agent before grinding, the strength of cement in 3 days and 28 days can be remarkably increased, and the actual dosage is less than 1/10 of ferrous sulfate. The method has the characteristics of high reduction rate, good selectivity, simple and convenient experimental operation and the like, and has cheap and easily obtained raw materials and very high application prospect.

[ summary of the invention ]

The invention provides a hexavalent chromium reducing agent and a preparation method thereof, and the prepared hexavalent chromium reducing agent has excellent performance, is environment-friendly, simple and convenient and has low price.

In order to solve the technical problems, the invention adopts the following technical scheme:

a hexavalent chromium reducing agent comprising: 11-23 parts of ferrous ions, 2-9 parts of stannous ions, 2-4 parts of heteroetherified melamine resin, 1-2 parts of sodium para-aminosalicylate, 0.2-0.4 part of nano-alumina, 40-60 parts of solvent, 4-6 parts of dispersant and 2-4 parts of stabilizer; the solvent is triethanolamine, ethylenediamine and water in a ratio of 2-4: 1-2: 6-8; the stabilizer is lignosulfonate.

Further, the hexavalent chromium reducing agent comprises: 17 parts by weight of ferrous ions, 5.5 parts by weight of stannous ions, 3 parts by weight of heteroetherified melamine resin, 1.5 parts by weight of sodium para-aminosalicylate, 0.3 part by weight of nano-alumina, 50 parts by weight of solvent, 5 parts by weight of dispersant, and 3 parts by weight of stabilizer II, wherein the solvent is triethanolamine, ethylenediamine and water in a ratio of 3: 1.5: 7.

Further, the hexavalent chromium reducing agent, wherein the stannous ion is derived from any one of stannous sulfate and stannous chloride or a mixture of the two.

Further, the hexavalent chromium reducing agent, wherein the ferrous ion is derived from any one of ferrous sulfate, ferrous chloride or a mixture of the two.

Further, the hexavalent chromium reducing agent, wherein the lignosulfonate is calcium lignosulfonate.

Further, the hexavalent chromium reducing agent, wherein the dispersant is one or a mixture of two of polyethylene glycol and triisopropanolamine, wherein the molecular weight of the polyethylene glycol is 200-400.

Further, the hexavalent chromium reducing agent is prepared by the method that triethanolamine is used for adjusting the pH value of a formaldehyde aqueous solution to 10-11, then melamine and the formaldehyde aqueous solution are mixed according to a proportion, the mixture is heated to 70-80 ℃, after the color of the mixed solution is gradually changed from white to clear and transparent, methanol and butanol are added for continuous reaction for 2-4 hours, and the hetereetherified melamine resin is obtained respectively; the molar ratio of the raw materials of melamine, formaldehyde, methanol and butanol in the hetereetherified melamine resin is 1: 5: 3.

The preparation method of the hexavalent chromium reducing agent comprises the following steps:

(1) uniformly mixing a solvent, ferrous ions, stannous ions and a stabilizer at the temperature of 20-40 ℃, and filtering by using a 200-mesh screen to obtain a first mixture;

(2) adding a dispersing agent into the first mixture, and uniformly mixing;

(3) and (3) uniformly mixing the heteroetherification melamine resin, the sodium p-aminosalicylate and the nano aluminum oxide, adding the mixture into the solution obtained in the step (2), uniformly mixing, and filtering by using a 200-mesh screen.

Compared with the prior art, the hexavalent chromium reducing agent greatly reduces the using amounts of a dispersing agent and a stabilizing agent, and meanwhile, the stabilizing agent lignosulfonate has certain environmental protection problems.

[ detailed description ] embodiments

In order to facilitate a better understanding of the invention, the following examples are given to illustrate, but not to limit the scope of the invention.

A hexavalent chromium reducing agent comprising: 11-23 parts of ferrous ions, 2-9 parts of stannous ions, 2-4 parts of heteroetherified melamine resin, 1-2 parts of sodium para-aminosalicylate, 0.2-0.4 part of nano-alumina, 40-60 parts of solvent, 4-6 parts of dispersant and 2-4 parts of stabilizer; the solvent is triethanolamine, ethylenediamine and water in a ratio of 3: 1.5: 7; the stabilizer is lignosulfonate.

The stannous ion is derived from stannous chloride. The ferrous ion is derived from ferrous chloride. The lignosulfonate is calcium lignosulfonate. The dispersant is polyethylene glycol, and the molecular weight of the polyethylene glycol is 200-400.

The preparation method of the hetermanized melamine resin comprises the steps of adjusting the pH value of a formaldehyde aqueous solution to 10-11 by using triethanolamine, then mixing melamine and the formaldehyde aqueous solution in proportion, heating to 75 ℃, adding methanol and butanol to continue to react for 3 hours after the color of the mixed solution is gradually changed from white to clear and transparent, and respectively obtaining hetermanized melamine resin; the molar ratio of the raw materials of melamine, formaldehyde, methanol and butanol in the hetereetherified melamine resin is 1: 5: 3.

The preparation method of the hexavalent chromium reducing agent comprises the following steps:

(1) uniformly mixing a solvent, ferrous ions, stannous ions and a stabilizer at 30 ℃, and filtering by using a 200-mesh screen to obtain a first mixture;

(2) adding a dispersing agent into the first mixture, and uniformly mixing;

(3) and (3) uniformly mixing the heteroetherification melamine resin, the sodium p-aminosalicylate and the nano aluminum oxide, adding the mixture into the solution obtained in the step (2), uniformly mixing, and filtering by using a 200-mesh screen.