This paper describes the concept of controlling the advancement speed of the shearer, the objective

of which is to eliminate switching the devices off to the devices in the longwall and in the adjacent

galleries. This is connected with the threshold limit value of 2% for the methane concentration in the

air stream flowing out from the longwall heading, or 1% methane in the air flowing to the longwall.

Equations were formulated which represent the emission of methane from the mined body of coal in the

longwall and from the winnings on the conveyors in order to develop the numerical procedures enabling

a computer simulation of the mining process with a longwall shearer and haulage of the winnings. The

distribution model of air, methane and firedamp, and the model of the goaf and a methanometry method

which already exist in the Ventgraph-Plus programme, and the model of the methane emission from the

mined longwall body of coal, together with the model of the methane emission from the winnings on

conveyors and the model of the logic circuit to calculate the required advancement speed of the shearer

together all form a set that enables simulations of the control used for a longwall shearer in the mining

process. This simulation provides a means for making a comparison of the output of the mining in the

case of work using a control system for the speed advancement of the shearer and the mining performance

without this circuit in a situation when switching the devices off occurs as a consequence of exceeding

the 2% threshold limit value of the methane concentration. The algorithm to control a shearer developed

for a computer simulation considers a simpler case, where the logic circuit only employs the methane

concentration signal from a methane detector situated in the longwall gallery close to the longwall outlet.