Introduction of several new mineral dryers

There are many kinds of mineral dryers. Many dryers used for drying coal can be used for mineral drying, such as rotary dryer, fluidized bed dryer, airflow dryer, etc. Here only a new dryer is introduced.

Spray dryer

Spray drying has been applied more and more widely in mining industry, especially in the aspect of drying of floatation concentrate. Spray drying has gradually replaced traditional rotary drying and kiln drying.

Spray drying has the following advantages:

(1) The bottom flow of the thickener can be directly extracted for drying, and the colloidal suspension can be directly turned into dry product, avoiding the difficult problem of colloidal suspension filtration;

(2) It can not only meet the needs of flash smelting, but also reduce the fuel consumption in smelting or purification process;

(3) The product is almost dry, easy to handle, less product loss and environmental pollution;

(4) Spontaneous combustion materials (materials easy to spontaneous combustion when the humidity is 3% - 5%) can be quickly dried to absolutely dry and become inert substances;

(5) Easy to operate and control, high thermal efficiency.

The solid content in the suspension is generally 55% - 70)%. Use a rotary atomizer. The inlet temperature can be as high as 500-1000 ℃, so the thermal economy is good. The exhaust temperature is generally 110-150 ℃. The temperature of the dry product is much lower. The air inlet pipe of the dryer should be made of refractory materials. The dry product is discharged into the conveying system from the bottom of the conical drying chamber. The entrained particles can be recovered from the waste gas by high-efficiency electrostatic precipitator or high-efficiency cyclone separator combined with wet scrubbing device.

Due to the abrasive property of mineral suspension, reducing the wear of atomizer to prolong its service life has always been a research topic. ^A new atomizer suitable for abrasive suspension has been developed. The atomizer's spray tray is equipped with a number of diversion village bushes made of wear-resistant powder metallurgy, and the diversion bushes are arranged properly so that the hydrodynamic effect produced by the liquid flow in the tray can create a protective layer formed by the suspension in the inner chamber, thereby providing wear protection by using the suspension itself. The guide bushing can be rotated 90 ° at regular intervals to increase their service life by 4 times.

At present, the products treated by spray drying are mainly chromium enrichment, copper enrichment, lead manganese manganese zinc enrichment, yellow cake, precious metal mud, zinc slag and phosphate.