Method for preparing micron-grade stannic oxide powder

Abstract

The invention discloses a method for preparing micron-grade stannic oxide powder which is applicable to conductive glass, semiconductor materials, high-class ceramic colored glaze materials or electric operation. The method comprises the following steps: dropping an ammonium bicarbonate solution, an ammonium carbonate solution or a mixture solution of ammonium bicarbonate and ammonium carbonate into a reagent-grade sodium stannate solution, controlling the pH value of a reaction liquid to be within the range of 9.0-10.0 so as to prepare tin hydroxide hydrate with high-dispersity, subsequently pulping the tin hydroxide hydrate by using pure water, further conditioning the pH value of the tin hydroxide hydrate pulp so as to obtain metastannic acid, and finally putting metastannic acid solid into a high-temperature furnace to be calcined and dehydrated so as to obtain the high-purity micron-grade stannic oxide powder. According to the method disclosed by the invention, micron-grade powder can be prepared without crushing, the production process is environment-friendly, the production equipment is simple, industrialization is easy to achieve, the micron-grade stannic oxide powder product prepared by using the method disclosed by the invention is small in particle size, high in purity, single in component and capable of meeting the requirements of conductive glass, semiconductor materials, high-class ceramic colored glaze materials or electric operation.

Description

technical field [0001] The present invention relates to a preparation method of tin chemical products, in particular to a preparation method of tin dioxide, more specifically to a micron-scale tin dioxide suitable for conductive glass, semiconductor materials, high-end ceramic color glazes or electricians. The preparation method of tin powder. Background technique [0002] Tin dioxide is an important tin chemical product, which is widely used in ceramic color glaze, conductive glass, nano-indium tin metal oxide, semiconductor materials, electronic contacts, electrical appliances, gas sensors, catalysts and other industries. It can be seen from the published literature that the preparation methods of tin dioxide mainly include the chemical synthesis method using tin-containing waste as raw material and the nitric acid method or high-temperature gasification method using tin ingot as raw material; Chinese patent CN102102150A discloses a A method for preparing tin dioxide from...

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Problems solved by technology

It can be seen from the published literature that the preparation methods of tin dioxide mainly include the chemical synthesis method using tin-containing waste as raw material and the nitric acid method or high-temperature gasification method using tin ingot as raw material; Chinese patent CN102102150A discloses a A method for preparing tin dioxide from tin-containing waste as a raw material. The method is a method for separating tin from waste tinplate and preparing tin dioxide. The main steps are: (1) crushing and screening the waste tinplate; (2) using soda aqueous solution Wash the undersize; (3) filter the washings, leach the filter residue with sodium hydroxide solution and an oxidizing agent, filter the leachate, and the filtrate is sodium stannate solution; (4) pass carbon dioxide into the sodium stannate solution, filter , washing to obtain a tin dioxide product; this preparation method has a long process route, a large demand for carbon dioxide, and a low utilization rate. The actual usage is 10-50 times that of the theoretical calculation, which is not very industrially feasible, and the product The impurity content is still high

Chinese patent CN1657417 discloses a method for producing tin dioxide by nitric acid method, which is a method for wet manufacturing metastannic acid and tin dioxide powder, the main steps of which are under the condition of airtight pressurization and oxygen addition, Control a certain temperature and reaction time, so that tin and nitric acid fully react to generate metastannic acid intermediate product, metastannic acid intermediate product is neutralized, washed and dried to obtain metastannic acid product; metastannic acid is calcined and crushed to obtain a particle size smaller than 10um fine tin dioxide product; this method uses nitric acid to prepare metastannic acid, a large amount of nitrogen oxides are produced, the process is not environmentally friendly, and nitric acid is a strong acid, and the product is easily polluted due to equipment corrosion. In addition, the product requires Fine tin dioxide products of 10um can only be achieved after crushing, which limits the use of products in high-end electronics and other fields

The technology for preparing high-purity tin dioxide by high-temperature gasification is relatively complicated, and is limited by equipment, resulting in high production costs and weak market competitiveness

[0003]Because the high-end fields such as electronic materials have high requirements on the purity and material properties of tin dioxide, the tin dioxide produced by traditional production methods cannot meet this demand. Most still rely on imported products

Chinese patent CN101532096 discloses a method for recovering tin from tin stripping waste liquid. The process is to use strong alkali to convert tin into sodium stannate solution, and then introduce carbon dioxide to prepare metastannic acid. Metastannic acid is washed and calcined to prepare di Tin oxide, because carbon dioxide is a weak acid, the reaction with sodium stannate solution is not complete, and metastannic acid is an amorphous colloid with strong adsorption capacity. Washing metastannic acid with pure water, the sodium carbonate ion wrapped in metastannic acid is still very high , up to 3%, sodium carbonate reacts with metastannic acid to form sodium stannate during calcination, which seriously corrodes the calcination equipment, and the finished product of tin dioxide cannot meet the needs of electronic industries such as conductive glass due to high impurities

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