PL46097B1 - - Google Patents

Description

2 Optfl on August 29, 1962. The patent is valid from July 12, 1961. Active clay substances such as: diatomites, bauxites, diatomaceous earths, siliceous earths, and especially bentonites and bentonite quantities, are characterized by the feature that they give gelatine suspensions with water and after mixing with loose material, such as a molding plate, it forms a compact plastic mass with it. The plasticity of bentonites and their high binding properties enable their use in the foundry, porcelain-faience and construction industries. Bentonites absorb a lot of water, turn into colloidal gel-like solutions, resembling gelatin, glue, starchmine solutions with their properties. They have the property of holding (binding) a certain amount of water, so they retain a constant percentage of the moisture necessary for the production of molds. They also have the advantageous features that they adsorb the gases emitted from the molds during casting. Colloidal, adsorptive and hygroscopic properties are related to the structure of the molecules as well as to the electric charges (ions) they contain. All the most important physical and chemical properties of bentonites, especially their water absorption capacity, plasticity and adsorption capacity, depend on the amount and type of hydroxide, hydrogen, sodium-potassium, calcium and magnesium ions present. ions are found in the raw material, others must be incorporated into the bentonites. During improper drying or roasting of bentonites, some ions are completely removed. In their place, new ions must be introduced by adding a suitable chemical substance. They can be introduced before drying or after drying or even after roasting. This is done by wetting with a solution of soda, sodium or potassium liquor. The essence of the invention is to introduce into the active earth, especially bentonite and to the amount of tonite ammonium, hydrogen and nitrate compounds. The nitrate group and the hydrogen are introduced in the form of nitric acid. It is intended to remove calcium carbonate from the raw material. The resulting nitrates, by attracting moisture, maintain a constant degree of humidity, increase the gel's strength and bond strength. This addition is small and should not exceed 1% by weight of the bentonite raw material. The next operation to increase the amount of ions is the introduction of ammonium ion by mixing dry bentonite obtained from drying at a temperature of up to 130 ° C with ammonia carbonate. nu. The introduced ammonium ion replenishes the hydroxide ions, which may have been completely or partially removed during drying, especially when the temperature exceeds 130 ° C, in order to increase the quantity and binding strength of the bentonite. The ammonium carbonate addition amounts to 0.25% to 1% with respect to the amount by weight of the dry bentonite substance. PL

Claims (1)

1. Patent claim A method for the production of binders (binders) for foundry from active earth, especially bentonite, characterized in that nitric acid is added to the wet bentonite in an amount up to T * / ow "sTósuric by weight to the amount of wet bentonite in order to remove carbonate of calcium and the formation of ions favoring the maintenance of a constant humidity and increasing the binding force, and after drying the mass thus obtained at a temperature of up to 130 ° C, ammonium carbonate in the amount of 0.25-1% by weight to the amount of dried mass in order to increase the smoothness and binding strength of bentonite. Barbara Ciechomska Roman Gizowski ZG "Ruch" W-wa, res. 702-62 B5 - 100 copies PL