I. Significance of Developing New Modern Lime Kiln Technology

Lime is the main and main auxiliary material for steel production, calcium carbide production, refractory production, alumina production. Especially in the new era, new technology, new products continue to develop calcium materials are more and more widely used. Practice has proved that modern lime kiln technology is indeed a very realistic and shortcut benefit bright spot for iron and steel enterprises, calcium carbide enterprises, coking enterprises and so on. At present, the profit per ton of lime has far exceeded the profit of tons of steel, tons of iron, tons of calcium carbide, tons of coke. Enterprises that have applied modern lime kiln technology have been greatly benefited, and have achieved greater social benefits. However, many enterprises are restricted by traditional management consciousness and management level and have not developed modern lime kiln production technology still rely on soil kiln lime production. Therefore, if we want to thoroughly control the pollution of soil kiln, we must also rely on the implementation of modern lime kiln to solve the problem of demand.

The so-called modern new technology lime kiln is a more scientific calcining lime process with environmental protection, energy saving function, mechanization and automation. Because this process adopts modern calcination thermal technology, it can make full use of energy, especially the gas that pollutes the environment as energy source and turn waste into treasure. This not only protects the environment, but also produces good quality and low cost lime. Its direct and indirect benefits, economic and social benefits are very considerable. This is the significance of popularizing new technology lime kiln.

2. Types of modern lime kiln technology

There are mixed kilns by fuel, that is, solid fuel, coke, coke powder, coal and gas kiln. Gas kiln includes blast furnace gas, coke oven gas, calcium carbide tail gas, furnace gas, natural gas and so on. According to the shape of the kiln, there are shaft kiln, rotary kiln, sleeve kiln, Vimast kiln (West Germany), Melz kiln (Switzerland), Fucas kiln (Italy) and so on. At the same time, there are positive pressure operation kiln and negative pressure operation kiln. The modern mixed kiln with 800 cubic meters per day output below 500 and the modern gas kiln with 250 cubic meters, especially the energy saving and environmental protection lime kiln with blast furnace gas and coke oven gas combustion, have been developed and designed. The design and manufacture of “lime kiln long flame burner” has solved the burning problem of high calorific value and short flame of coke oven gas, which can make full use of the remaining coke oven gas. From the original coke oven gas “lighting “, polluting the environment into a valuable energy for enterprises to create benefits. For small and medium-sized iron and steel enterprises, coking enterprises, calcium carbide enterprises, and refractory industry are very good energy saving, environmental protection, efficiency and effective ways.

3.THE BASIC PRINCIPLES AND THE TECHNOLOGY PROCESS

The main component of limestone is calcium carbonate, while the main component of lime is calcium oxide. The basic principle of burning lime is to decompose calcium carbonate in limestone into quicklime of calcium oxide and carbon dioxide with the help of high temperature. Its reaction formula is

CaCO2CaO CO2–42.5KcaI

Its process is that limestone and fuel are preheated in lime kilns (if gas fuel pipes and burners are fed) and decarbonized at 850 degrees, calcined at 1200 degrees, then cooled and unloaded out of the kiln. Its full calcination process is equivalent to being carried out in a sealed container. Different kiln shapes have different preheating, calcination, cooling and ash unloading methods. However, some process principles are the same: calcination temperature is 850-1200 degrees, preheating temperature is 100——850 degrees. The ash temperature is below 100 degrees. The raw material quality is high, the lime quality is good; the fuel calorific value is high, the quantity consumption is small; the limestone particle size is proportional to the calcination time; the quicklime activity degree is inversely proportional to the calcination time and the calcination temperature.