FINER SCREENS FOR COAL

Southland Times, Issue 23512, 19 May 1938, Page 6

FINER SCREENS FOR COAL

REDUCING WASTE AT MINES 4 NEW SYSTEM OPERATES ON OHAI FIELD At the request of the Minister of Mines (the Hon. P. C. Webb) the Southland Coal Owners’ Association recently agreed to reduce the mesh of the screens through which coal is passed, the purpose of the change being to reduce the percentage of small coal remaining after the household grade had been removed. This action was previously taken in the North Island with satisfactory results and the Minister recommended that the Southland companies take similar action. After consultation, the companies agreed to replace their existing screens with others of uniform size one inch round, and the change took effect on May 1. The reduction was comparatively small, Representing an average of one-eighth of an inch variation from the screens of different sizes previously in use at the mines.

The manager of a leading company told The Southland Times yesterday that consumers need not be afraid that the coal supplied in the future would be much smaller than in the past. There would certainly be slightly more small coal, but the" new screens installed were expected to give greater efficiency, and less dusty coal than before was likely to be included in household grade. During the first few days after the adoption of the new screens, stated the manager, there was some difficulty in securing the greatest efficiency in operation and several days elapsed before the most effective adjustments could be made. This might have been responsible for excessive dross in household coal since the beginning of the month, but there was now every reason to believe that the plants at all mines were giving satisfaction. Occasionally areas of unusually brittle coal were encountered in mining, but it was invariably found that this coal although small in size produced greater heat than coal with less tendency to break.