THE OREPUKI SHALE WORKS.

Taranaki Daily News, Volume XXXXII, Issue 200, 28 September 1900, Page 4

THE OREPUKI SHALE WORKS.

As the Orepuki Shale Works have been frequently mentioned in connection with the alterations in the Customs duties on oandles and kerosene, the following particulars about them, which we find in the Mines Keport, may interest many of our readers: — The plant which is being laid down at Orepuki is one of the latest and most improved type, the result of fifty years' research by many workers in Scotland. The shale-field has been tested over a large area and found to be nearly uniform in thickness, and giving a quantity of oil over the average shale in Scotland, where some shales give 120 to 130 gallons of oil per ton. When the shale comes out of the mine it is put into a breakingmachine, and when broken is raised into hoppers on top of the retorts. The shale in the retort is kept in continuous motion by machinery at the bottom, and when exhausted runs away at the bottom. By means of a fan the oily vapour is drawn from the retorts through a series of condensers, where the gases are cooled, and the liquid portion (oil and water) runs into a large receiving-tank, The gas is passed on through two large towers, where it is first passed through water, which robs it of its ammonia-gas, and then through oil, which robs it of its spirits. The gas then goes on to the retorts, where it is used for firing.

Sulphate of ammonia is extracted from the water which comes over along with the crude oil. and the crude oil is pumped up into a large tank, separated irom any water which it may contain, »nd then run into the still. The still is then heated up, and the oil-vapour passes over and is again condensed and run into a receiver. During the distillation steam is passed through the still to bring over the oil at a lower temperature, and preserve theparafflne molecule. After the distillation is

is finished there is coke left in the still, which is used for making moulders, blacking, and for burning in parlour : fires, as is gives a good heal and practically no ash. The oil in the receiver is next treated with sulpkuric acid and soda-hydrate and again distilled, and this time cut into light and heavy portions. From the light portion burning-oil is obtained, and from the heavy lubrlcatlng-oils. The light portion is again treated, distilled, and again treated and is finished burningoil. The heavy portion goes to the parafflne-shed, where it is frozen and the paraffine-wax extracted. The oily portion is then again treated and distilled, and cut up into the different grade of lubricating oil. These lubri-cating-oils are again frogen and more wax extracted, again treated, and are ready for the market. The paraffinewax is put into a sweating-house, where the temperature is gradually raised. Any oil which it contains comep away first, bringing a lot cf impurities with it, then the lower melting-point wax,

and lastly the high-melting-point wax, which all run inte different receivers. This process has generally to be gone through twice before it is ready for the final touch, which is to pass it through animal charcoal, which decolourises it. It is then run into cakes, and is ready j

for the market. The high-inelting point wax is rned for candle-making, and the lower melting-points are used for match-making and many other purposes. When dissolved in spirit low-melting-point waxmakes a splendid damp-repeller, and when put on a house in summer is said to last a long time. A coating of wax is said to preserve fruit and butcher's meat. It is used by brewers for coating the inside of beer-barrels, and by weavers in the manufacture of yarn and cloth. It is also used for making cork impervious to air and as a non-con-ductor by electricians. One of the bad uses it is put to is to adulterate sweetmeats. Paraffine-wax, when well refined, is a wax-like, white or colourless crystalline substance, and is not acted on by other acids or alkalies, and is one of the most stable substances known. .The spirit extiucted from the gas is called naphtha, and has a specific l gravity of 730 to 760, and is used for. extracting fats, oils and similar bodies, and in the preparation of paints and varnishes. The acids and soda tars,

when neutralised, are used for making' briquettes and for asphalting purposes. When theerections are completed, and the work in full going order, the works at Orepuki will put through 2000 gallons of crude oil per day, and this output can be doubled at a comparai tively small cost."