Coal Pyrite Research Articles

Reaction of pyritic sulphur in coal with lime and calcined dolomite during the coking process

Various reactions occur between pyrite (FeS 2) in coal and CaO to form CaS when a finely pulverized intimate mixture of coal and CaO is coked at 900 °C in an inert atmosphere. The effectiveness of lime and calcined dolomite (CaO.MgO) in promoting this reaction has been evaluated; calcined dolomite is somewhat more effective than lime over coal/ oxide weight ratios from 2.8 to 14. The degree of conversion of pyrite to calcium sulphide at a coal/calcined dolomite weight ratio of 7 has been determined as a function of time at 900 °C; coking time in excess of 2.5 h does not have a significant effect. It has been shown that the total sulphur lost on coking coal/lime mixtures decreases and the percentage of FeS, originating from the dissociation of pyrite, converted to CaS increases as the amount of lime added increases. But although the total sulphur content of coke produced in the presence of CaO is then higher than when the coal is coked without lime, the pyritic sulphur has been converted to CaS which is more amenable to chemical conversion to H 2S. A method is outlined for determining CaS in the coked mixture in the presence of FeS.

Quantitative analysis of pyrite in coal

Quantitative analysis of pyrite in coal

Closure to “Oxidation of Coal Mine Pyrite”

Closure to “Oxidation of Coal Mine Pyrite”

Discussion of “Oxidation of Coal Mine Pyrite”

Discussion of “Oxidation of Coal Mine Pyrite”

Pyritic Coal Balls from Oyake 5-Shaku Seam of Omine Colliery, Chikuho Coal Field, and a Consideration on the Original Plant Debris of the Coal

Pyritic Coal Balls from Oyake 5-Shaku Seam of Omine Colliery, Chikuho Coal Field, and a Consideration on the Original Plant Debris of the Coal

Bacterial Oxidation of Pyritic Materials in Coal

Applicability of the manometric method for studying the oxidation of pyritic material in the presence of bacteria has been demonstrated. Resting cells of Ferrobacillus ferrooxidans accelerated the oxidation of coal pyrites and coarsely crystalline marcasite, but were inactive on coarsely crystalline pyrite. Resting cells of Thiobacillus thiooxidans were inactive on all pyrites tested. Oxidation rates in the presence of Ferrobacillus were increased by reducing the particle size of pyritic samples, and, in one case, by removing the CaCO 3 from a calcite-containing sample.

Bacterial Oxidation of Pyritic Materials in Coal

Applicability of the manometric method for studying the oxidation of pyritic material in the presence of bacteria has been demonstrated. Resting cells of Ferrobacillus ferrooxidans accelerated the oxidation of coal pyrites and coarsely crystalline marcasite, but were inactive on coarsely crystalline pyrite. Resting cells of Thiobacillus thiooxidans were inactive on all pyrites tested. Oxidation rates in the presence of Ferrobacillus were increased by reducing the particle size of pyritic samples, and, in one case, by removing the CaCO(3) from a calcite-containing sample.