The Fuel Selection for Cement Rotary Kiln

In the calcination process of cement rotary kiln, a lot of coal will be used, but the quality of coal resources in our country is very low and the distribution is not even, which cause a huge price difference. For this reason, it is imperative to apply the latest technology in cement rotary kiln to use coal of low volatility and anthracite in the calcinations of cement clinker, thus reaching the goal of reducing cost and improving economic benefits.

Coal of low volatility is a very systematic working system in the calcinations of cement rotary kiln, and it makes use of advanced braize calcination equipment. Without advanced braize making equipment and clinker cooling equipment, the fuel of low volatility cannot be sufficiently calcined, then the use of this coal cannot reach the predictable effect in the rotary kiln. For this reason, we should see the preparation and calcinations of coal powder and the cooling of clinker as a whole to research its running process in the using process of coal of low volatility.

The fixed carbon content of coal of low volatility is very high and it has very compact structure. When a small part of coal of low volatility is clacined in the cement kiln, the heat it releases cannot reach the temperature needed to catch fire by fixed carbon. Coal of low volatility can catch fire when reaching 550-660℃ which is 50-100℃ higher than soft coal. To get the same calcinations degree, it will need the time 1.5~2 times of common soft coal. After careful research and development, we know that the fineness of coal powder is the decisive factor of catching fire, and only by adjusting the fineness of coal powders can the firing temperature and time be better controlled in the calcinations process of rotary cement kiln. For this reason, to make sure the coal of low volatility smoothly burned, we should reduce the fineness of coal powder.

To ensure the temperature gradient in the horizontal kiln and good heat transfer environment, we have to raise the secondary air temperature. At the same time, the faster the high-temperature secondary air temperature replaced is discharged, the faster the coal powders will be calcined. The negative pressure under high thrust and high air wind speed, more secondary hot air will be entrained and it can rapidly heat and oxygenate the carbon granules, which is conducive to the fast calcination of carbon granules inside the cement rotary kiln.