Drying technology for preparing high content industrial solid sodium cyanide product

Abstract

The invention discloses a drying technique for preparing high-content industrial solid NaCl products, i.e. by controlling the feed quantity, it feeds sodium prussiate through a spiral transporter into the drying room with a rotary flash-vaporization drier, and at the same time, feeds normal-temperature air after filtered to an electric air heater for heating and then bellows the heated air through the bottom of the drying chamber into the drying chamber; makes the dried material powder leave the drying chamber together with the air flow, separates by a cyclone separator to discharge the material through a rotary valve to enter in the next working procedure. It shortens the technical flow, reduces energy consumption, and improves productivity and quality and simultaneously reduces the discharge of waste gas and waste water, and solves the problems of existing techniques, like high energy consumption, low output, high labor strength of workers, inconsistent product quality, etc.

Description

1. Technical field [0001] The invention relates to a drying process for preparing high-content industrial solid sodium cyanide products. 2. Background technology [0002] Sodium cyanide belongs to the inorganic salts in chemicals, and sodium cyanide has two types of liquid and solid as products. High content (NaCN content ≥ 98.0%) solid sodium cyanide is mainly used in chemical industry, light industry, electroplating, gold, medicine and other industries, with a wide range of uses and a large amount of use. [0003] All manufacturers of solid sodium cyanide in the world have roughly the same process route, that is, first use caustic soda (NaOH) and hydrocyanic acid (HCN) to react to generate liquid sodium cyanide, and then evaporate, crystallize, centrifugally dehydrate and granulate it , drying (further dehydration), tablet molding and metered packaging to obtain solid sodium cyanide products. In this technological process, only the first reaction process is a chemical re...

AI Technical Summary

Problems solved by technology

[0007] 1. When using fluidized bed drying, it is first necessary to granulate the wet sodium cyanide crystals after dehydration by the centrifuge, otherwise, the wet crystals of sodium cyanide powder will easily block the mesh of the fluidized bed, thereby reducing the gas-solid two-phase mass transfer and heat transfer surface area , not easy to dry, increasing energy consumption

[0008] 2. The fluidized bed drying system has a total of 25 large and small equipment (excluding waste gas treatment system), covering an area of ​​216m 2 , the power consumption is up to 280kw; the process is long, the equipment is blocked more frequently, and the exhaust gas emission is up to 40000m 3 / hr, the wastewater discharge rate reaches 9.0t / hr, and the concentration of cyanide in the wastewater before treatment reaches more than 1200mg / l

[0009] 3. Fluidized bed drying uses 1.0MPa, 250°C steam as the heat source, the steam consumption reaches 2.8t / hr, and the heat energy utilization rate is not high; the material stays in the dryer for up to 30 minutes, and is easy to mix with water and air. Carbon dioxide reacts chemically, making it difficult to further improve the quality

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