PRODUCTION OF ALKALI METAL CARBONATES AND/OR BICARBONATES FROM ALKALI METAL SULPHATES

    公开(公告)号:US20240051836A1

    公开(公告)日:2024-02-15

    申请号:US18037669

    申请日:2021-11-18

    IPC分类号: C01D7/00 C01D7/24

    CPC分类号: C01D7/00 C01D7/24

    摘要: The invention provides a method of producing a carbonate or a bicarbonate of an alkali metal, in solid form, from a sulphate of the alkali metal. The method includes, in a first reaction step, reacting, in aqueous medium, a sulphate of an alkali metal with one or more alkaline earth metal sulphides, thus forming an aqueous solution of one or more sulphides of the alkali metal and one or more sulphates of the alkaline earth metal in solid form. The method also includes, in a second reaction step, in the aqueous solution of one or more sulphides of the alkali metal, reacting the one or more sulphides of the alkali metal with carbon dioxide (CO2) in gaseous form, thus forming an aqueous solution of a bicarbonate of the alkali metal and gaseous hydrogen sulphide. The method further includes, in a recovery step, recovering a carbonate or the bicarbonate of the alkali metal, in solid form, from the aqueous solution of the bicarbonate of the alkali metal.

    Method for preparing potassium chloride from carnallite

    公开(公告)号:US11851340B2

    公开(公告)日:2023-12-26

    申请号:US17997824

    申请日:2021-04-30

    发明人: Min Wang Lijie Shi

    IPC分类号: C01D3/06

    CPC分类号: C01D3/06

    摘要: A method for preparing potassium chloride from carnallite includes: carrying out high-temperature water solution mining treatment on carnallite with fresh water to obtain potassium-rich saturated brine; mixing the potassium-rich saturated brine, a sylvine saturated solution, and bittern for mixing brine, evaporation and decomposition to obtain artificial sylvine; and carrying out low-temperature selective dissolution treatment on the artificial sylvine with fresh water to prepare potassium chloride. The carnallite is mined by using hot water, which reduces the content of sodium chloride in the potassium-rich saturated brine; artificial sylvine is only subjected to low-temperature selective dissolution once, which avoids unnecessary energy consumption and impurity accumulation unnecessary for multifold cycles of thermal dissolution-cold crystallization treatment of sylvine while guaranteeing the high yield and high quality of potassium chloride. The method is suitable for different grades of carnallite, has extremely strong adaptability and loose technical conditions, and is conducive to promotion and implementation.

    Systems and methods for recovering salts, aluminum, alumina and ammonia from salt slag waste generated in aluminum recycling

    公开(公告)号:US11834343B2

    公开(公告)日:2023-12-05

    申请号:US17097655

    申请日:2020-11-13

    摘要: The disclosed technology includes a method for producing ultrafine alumina from salt slag waste generated in aluminum recycling useful in the manufacture of durable ceramic products; a system for recovering alumina from salt slag waste; a method and systems for recovering salts, aluminum and alumina from salt slag waste; and a method and systems of capturing ammonia in a process recovering salts, aluminum and alumina from salt slag waste. The methods and systems provided crush the dry particles of the salt slag waste, scrub the slag with water, and with steam and by means of a vented alumina press, dewater the scrubbed slag particles. In some methods and systems of the disclosed technology, the particles of the pressed alumina cake are further reduced. In some methods and systems, the salt in the salt effluent is crystalized. In some methods and systems of the disclosed technology, the ammonia is contained and captured.