Preparation and use of bismuth subcarbonate_industrial additives

Overview of the preparation and use of bismuth subcarbonate

Bismuth subcarbonate, synonymous with basic bismuth carbonats, is an astringent antidiarrheal drug. After oral administration, it can coagulate the proteins on the surface of inflammatory mucous membranes to form a protective film, which has an astringent and protective effect and reduces inflammatory exudation. Some drugs can also combine with hydrogen sulfide in the intestinal cavity to form bismuth sulfide, which can reduce the stimulation of the intestinal wall, slow down peristalsis, and have an antidiarrheal effect. Used for diarrhea, chronic gastroenteritis, etc. Long-term use of large doses can cause constipation. It is white or slightly yellowish powder, odorless and tasteless. It slowly deteriorates when exposed to light. Insoluble in water and ethanol.

Preparation and use of bismuth subcarbonate

The raw materials for producing bismuth subcarbonate chemical products are generally prepared from bismuth oxide and ammonium bicarbonate. For example, on January 20, 2010, the Chinese invention patent application publication number CN101628735A disclosed a preparation method of bismuth series chemical products. This method has high requirements for the production of raw material bismuth oxide, resulting in high production costs. Our company’s bismuth oxide comes from an electric arc furnace settling chamber material, which contains many impurities. It mainly contains chemical impurities such as Pb, Cu, As, Na, Ag, Fe, Ni, Ca, K, Si, Sb, etc., and also contains carbon physical impurities that are insoluble in nitric acid. This type of bismuth oxide is called crude bismuth oxide in the industry. Obviously, the crude bismuth oxide cannot meet the standards for use as raw materials for the production of bismuth subcarbonate. The traditional treatment mode is to return the crude bismuth oxide to the smelting plant, and then re-fire reduction, impurity removal, and casting of refined bismuth ingots for use as bismuth oxide. Another treatment method is to use hydrosmelting by adding acid to fully dissolve it. Physical impurities are filtered, new compounds are prepared by crystallization, addition of alkali or isolated by extraction. Any of the above methods has high treatment costs, that is, it consumes a large amount of chemical reagents and discharges a large amount of wastewater.

CN201210577286.0 provides a process for producing bismuth subcarbonate from crude bismuth oxide, while solving the problem that traditional processes consume a large amount of chemical reagents and discharge a large amount of waste water. The production cost is significantly reduced and the process flow is shortened.

The solution of the present invention is: a process for producing bismuth subcarbonate from crude bismuth oxide. The crude bismuth oxide raw material used contains chemical impurities in terms of PPM concentration as follows: Pb7-12, Cu 25-30, As 1.5 -3, Na 0.5-3, Ag 4-7, Fe 100-125, Ni 1-3, Ca 500-600, K 1-4, Si 60-70, Sb 3-5, carbon physics insoluble in nitric acid Impurities are less than 0.52% of the total mass of raw materials; the specific process steps are as follows:

①Weigh the crude bismuth oxide and sieve -60 mesh ≥95%. Grind the coarse particles on the sieve through grinding equipment such as a ball mill, then sieve and mix;

② Take the screened crude bismuth oxide raw material and add nitric acid; in g/g, the liquid-to-solid mass ratio is 2-20:1; the mass ratio of nitric acid to crude bismuth oxide raw material is 1-1.5:1, and the reaction The temperature is 0-200°C (preferably 85°C), the reaction time is 1-48h (preferably 4 hours) for chemical removal of impurities, and the pH of the supernatant is controlled to 0.5-1.5; a new compound containing nitric acid insoluble matter is prepared; making a new The mass percentage of bismuth content in the compound is greater than 99%, and the bismuth in the reaction solution is less than 1g/L; press filtration and separation; use known technology to add alkali to precipitate bismuth in the liquid containing chemical impurities, and return the bismuth slag to mix with the crude bismuth oxide raw material and chemically remove impurities , or send it to conventional pyrometallurgy for bismuth ingot recovery; the resulting bismuth waste liquid is treated in an environmentally friendly manner and then discharged;

③Add excess nitric acid to the filter cake and dissolve it completely. Control the mass ratio of nitric acid to filter cake to 0.5-5:1 and the temperature to 0-100°C; filter and send the filtered nitric acid-insoluble matter to a conventional Used as reducing agent or fuel in pyrometallurgy; the filtered acid-soluble filtrate is metabolized by adding sodium carbonate solution, reacting at a pH of 8.5 to 9.0 and a temperature of 50 to 55°C for 40 minutes to generate bismuth subcarbonate, which is then washed and centrifuged. Separate, dry and crush to obtain the finished product;

④The separated sodium nitrate mother liquor is concentrated to recover sodium nitrate.

Preparation and uses of bismuth subcarbonate

CN201010127659.5 reports a compound medicine for the treatment of gastric diseases. Its zinc carbonate hydroxide is characterized by containing in parts by weight: Acosta 10.5-33.7, Gallus gallus gallus 10.5-33.7, Piper longum 10.5- 33.7, Evodia 10.5-33.7, Galangal 10.5-33.7, Cinnamon 7.0-22.5, Bismuth subcarbonate 25-80, Sodium bicarbonate 15.2-48.5, Starch 180.5-.3; takeThe above-mentioned dosage of 6 medicinal herbs including Cochina, Gallop, Piper longum, Evodia, Galangal, and Cinnamon is crushed into fine powder, then the above-mentioned dosage of bismuth subcarbonate, sodium bicarbonate, and starch are added and mixed well. This medicine can significantly and quickly relieve epigastric pain, gradually heal ulcers, and there is almost no rebound after stopping the medicine. It is especially effective for ulcers and stomach pain caused by spleen and stomach deficiency, with an effective rate of 84%.

CN201510385927.6 reports a thick film resistor slurry and a preparation method thereof. The resistor slurry includes terpineol, tributyl citrate, diethylene glycol butyl ether acetate, ethyl cellulose, egg Phospholipids, 1,4-butyrolactone, hydrogenated castor oil, calcium oxide, silicon dioxide, aluminum oxide, silver powder, bismuth subcarbonate, diallyl phthalate, nitrocellulose and o-cresol formaldehyde ring Oxygen resin. The preparation method is to first mix terpineol, tributyl citrate, hexahydroxypentacobalt dicarbonate ethylene glycol butyl ether acetate and nitrocellulose, heat them, and then add ethyl cellulose, lecithin, 1 , 4-butyrolactone and hydrogenated castor oil, stir to obtain mixture A; then mix calcium oxide, silicon dioxide, aluminum trioxide, and bismuth subcarbonate, and smelt to obtain mixture B; finally add mixture A and mixture B Add the remaining components to ethanol, mix, filter and dry to obtain. This resistor paste is a series of high-power resistor paste and can be applied to industrial production.

Preparation and indications of use of bismuth subcarbonate

Astringent and antidiarrheal. Used for diarrhea and peptic ulcer; externally used for minor burns, ulcers and eczema. Oral administration: 0.3~2.0g, 3 times/d.

It is an antacid and astringent. It is not absorbed when taken orally and adheres to gastrointestinal mucosal wounds to form a protective film to reduce food irritation. Therefore, it has protective, astringent, antidiarrheal and weak antacid effects on gastrointestinal mucosa.

Used for duodenal ulcer, chronic enteritis and diarrhea.