BRIQUETTED COAL.

Auckland Star, Volume LX, Issue 282, 28 November 1929, Page 7

BRIQUETTED COAL.

SMOKELESS FUEL MANUFACTURE IN WAIKATO, REVOLUTIONISING THE INDUSTRY LOSSES THROUGH ELECTRIC POWER.

Waikato district collierics have been hard liit by the advent of hydro-electric power, but efforts are being made to combat the consequent loss to the market by presenting slack coal formerly used extensively by the Auckland Power Board in a form for use by other consumers.

"Governmejnt hydro-electrical power has affected the coal industry right throughout New Zealand, but probably more seriously in the Waikato than elsewhere," stated the president of the New Zealand Coalmine Owners' Association (Mr. W. 1). Holgate) in presenting his report- to the annual meeting in Wellington yesterday. "The Waikato coal mines have been supplying the Auckland Power Board with large quantities of slack coals each year for several years past. The supply of current from Ara-

puni station has done away with the use of the board's steam plant at Auckland, and has destroyed the market'for the coal formerly used. Anticipating this loss of market, the Waikato coal companies have investigated the English and Continental systems of coal distillation, with the object of converting the slack formerly used by the Power Board into fuel for other consumers. Many bulk samples were sent to England and Europe for experimental treatments.

German Process Adopted. "Early in the investigation it was indicated that the process finally adopted would have to come from Germany, because the coals there are of the same character as the Waikato coals. There are several German processes, but the one finally decided on by the Waikato companies is knowli as the Lurgi process, with the following stages of treatment: — (1) To carbonise a lignite or brown coal at such a temperature as would leave between 7 per cent and 10 per ceiit of" volatile matter in a semicoke; (2) to distill tar products, fuel oil and pitch; (3) to briquette the whole or part of the semi-coke, using the pitch produced in the second stage as part of the binder. Capacity of Plant.

■ "The semi-coke, which is the product principally aimed at by, the Waikato companies, will amount to 50 per cent of the weight of the original coal. This fuel is practically smokeless and sparkless and is guaranteed to have a certain calorific value of over 12,500 B.T.U.'s. It is believed that this fuel will be entirely suitable for railway use and also for domestic water heaters, for domestic purposes generally and for all power plants; The capacity of the new plant now ordered is 40,000 tons of smokeless high-grade briquettes per annum, 2000 tons of deisal oil, 3200 tons of fuel oil, and 2900 tons of pitch. The plant can be added to in units as may be desired.

"The enterprise shown by the companies in connection with the new treatment • deserves the commendation of the public," adds the report. "They are the pioneers in a new development of the coal industry, which may revolutionise its whole outlook."