Metallurgical lime production line technology

A typical configuration of the rotary kiln, is the vertical preheater kiln+ rotary kiln + vertical cooler.

Steel (steel desulfurization, iron sintering), accounting for 20% of the amount of metallurgical lime; calcium carbide (calcium carbide production of ethylene), 6%; non-ferrous metals (such as Bayer process alumina), 3%; dry or wet desulfurization (2%).

Process Features

Selection of rotary kiln with preheater. Vertical preheater can withstand higher exhaust gas temperature, can get in the preheater lime partially decomposed, compared with other types of low kiln heat consumption, heat per kilogram of lime consumption is less than 5500 kJ.   

1, vertical preheater

Low pressure drop of the preheater, reduce flue gas resistance loss in the preheater, reducing exhaust device power consumption. From high temperature kiln to heat the flue gas directly through the material layer, sufficient heat exchange with the limestone, limestone preheating temperature up to 900 ℃, there are nearly 30% of the decomposition of limestone, the exhaust gas temperature is less than 270 ℃.

→ hydraulic pusher to kiln feed.

→ preheater at the top of the silo with a level gauge control, ultrasonic level meter, control room to achieve low material level alarm and interlock feeding system, ensuring highly stable layer material preheater.

→ In addition to the top of the preheater uses hanging brick, the other parts are made of refractory castable, less brick, masonry simple.

→ preheater small sports equipment, small equipment maintenance.

2, rotary kiln

→ use stubby-type rotary kiln. As the diameter of 3.5m, the kiln length 55m, land conservation.

→ kiln using speed motor drive, and an auxiliary motor, stable, flexible adjustment.

→ A spring sheet kiln sealing structure is simple, reliable, good sealing effect.

3, vertical cooler

→ cooler is divided into four zones, each zone can be controlled separately.

→ cooling air and direct contact with hot material, good cooling effect, the ash temperature above about ambient temperature about 80 ℃, the secondary air can be preheated to a temperature above 600 ℃, is conducive to firing.

→ coolers have no moving parts, low maintenance equipment.

4, a four-channel pulverized coal combustion burner pulverized coal (pulverized coal burner)

Four-channel pulverized coal burner means is a big speed difference between the new burner, the cement industry has been widely used. Using the same co-flow to big speed difference principle, the pulverized coal ejection speed and angle adjustment, a negative pressure zone in the central region of the burner, can promote the mixing of secondary air and pulverized coal, pulverized coal heating up fast reached ignition temperature.

→ primary air less, about 8% of the theoretical amount of combustion air; wind coal discharge rate of about 25-35m / s at the nozzle; swirling wind in the discharge nozzle velocity of about 120-180 m / s; DC wind speed at the discharge nozzle is 140-200 m / s; the center of the wind the wind is about 2-6% of the amount of primary air.

→ flame shape can be flexibly adjusted to suit the needs kiln firing lime.

→ coal adaptability, combustible low-quality coal.

→ calcining kiln and the brush will not be deflected burning skin.

5, type of kiln exhaust gas treatment using LCM long bag pulse dust collector

LCM long bag pulse dust collector type combines the advantages of sub-room cleaning and pulse cleaning, and lengthened bag, give full play to the role of air force jet dust to prevent dust reattachment and out of control, so as to improve filtration rate, cleaning save energy and prolong the effect of the filter bag life.