Review of experimental methods to determine spontaneous combustion susceptibility of coal – Indian context

This paper presents a critical review of the different techniques developed to investigate the susceptibility of coal to spontaneous combustion and fire. These methods may be sub-classified into the two following areas: (1) Basic coal characterisation studies (chemical constituents) and their influence on spontaneous combustion susceptibility. (2) Test methods to assess the susceptibility of a coal sample to spontaneous combustion. This is followed by a critical literature review that summarises previous research with special emphasis given to Indian coals

A Rapid and Accurate Method for Equilibration of Coal for Moisture Estimation at 60 Percent Relative Humidity

A rapid method for the equilibration of coal for moisture estimation at 60 per cent relative humidity is described. The method ensures correct equilibration followed by moisture estimation on a number of samples in one working day. It is thus, an improvement over the existing methods [1, 2], in so far as the quickness of the equilibration of the sample is concerned as well better repeatability

Indian coals for sponge iron process

In contrast to conventional two stage process of steel making via blast furnace, direct steel making with pre-reduced iron ores or agglomerates have attracted attention in recent time. This is particularly so for developing countries where there is availability of other raw materials for iron making but there is dearth of, or limited resources of coking coal and abundant supply of non-coking coals. In terms of energy equivalent, availability of solid fuel is many hundred times more than that of natural gas. Extensive attempts have therefore been made to utilize non-coking coals to produce iron by non-conventional methods such as direct reduction process. The solid iron produced by reduction technique known as ‘sponge’ can then be transformed into steel by melting. An attempt has been made in the paper to indicate the available resources of Indian coals, their nature and property which may be considered suitable for the production of sponge iron either as such or after beneficiation. Indications have also been given for the possibility of utilising char from the fluid bed carbonisation of non-coking coal where such material can be obtained from an integrated formed coke plant

Experiments with metallic water troughs in a 300 ft. (91.5m) long surface steel gallery

Experiments conducted with metallic water troughs in the coal dust explosion suface steel gallery reveal that water troughs are quite effective in arresting the spread of flame beyond the zone of the barrier. It is also found that when the troughs are free to be dislodged from the position of rest, flame extinction is more effective than the situation when the water troughs are fixed to the body of the gallery. The flame is found to move with an accelerated velocity and the distance of the quenching zone from the position of the barrier is dependent on the concentration of water present. There is an optimum concentration of water to be present in the barrier for preventing the propagation of explosion