Abstract: Composition and method for producing a low-sulphur, free-machining steel, substantially free of lead and including in weight percent about 0.05-0.40 copper, 0.005-0.040 tellurium, 0.002-0.35 bismuth, 0.002-0.05 tin, up to 0.55 carbon, and less than 0.25 sulphur, traces (up to about 0.005 weight percent) of barium, and the balance being iron. The elements bismuth, tellurium and tin are added as a molten alloy to the molten steel and uniformly distributed therethrough. The elements copper and barium can be added separately into the steel stream ahead of the molten addition inflow. The mass is then cooled to provide a solid metal casting substantially free of blemishes and free of surface checking and tearing. The casting is characterized by enhanced machining properties.

Abstract: Composition and continuous casting method for producing a low-sulphur, free-machining steel, substantially free of lead and including in weight percent about 0.05-0.40 copper, 0.005-0.040 tellurium, 0.002-0.15 bismuth, 0.002-0.05 tin, up to 0.55 carbon, and less than 0.25 sulphur, traces (up to about 0.005 weight percent) of barium, and the balance being iron. The elements bismuth, tellurium and tin are added as a molten alloy to the molten steel and uniformly distributed therethrough. The elements copper and barium can be added separately into the steel stream ahead of the molten addition inflow. The mass is then cooled to provide a solid metal casting substantially free of blemishes and relatively free of surface checking and tearing. The casting is characterized by enhanced machining properties.

Abstract: Alloying ingredients are added as shot to a pouring stream of molten steel flowing from a ladle to a casting mold. The size of the shot is controlled to enhance the recovery and uniformity of distribution in the steel of the alloying ingredients.

Abstract: In a formed coke process of the type in which carbonization and calcination of coal is carried out prior to briquetting, the hot calcined char is cooled by means of a hydrogen-rich gas at superatmospheric pressure so as to effect concurrent cooling and desulfurization of the char. High sulfur coal containing 1.5 to 4 wt. % sulfur can be used while obtaining a char and a formed coke product with a sulfur content of 0.8 wt. % or less. The cooling can be done in two stages: (1) a first stage in which sulfur removal and cooling to a temperature not lower than about 800.degree. F. are accomplished with a hydrogen-rich gas, and (2) a second stage in which further cooling to about 200.degree. F. or less is accomplished with an inert gas.

Abstract: A steel billet is produced having free machining properties and substantially devoid of surface-cracking in the as-deformed condition and without surface conditioning. The steel contains bismuth and tellurium and may contain lead but in a smaller amount than is conventional in leaded, free machining steels. The billet was hot deformed at a temperature above about 920.degree. C. (1700.degree. F.) and below 1150.degree. C. (2100.degree. F.). The steel contains inclusions of MnTe and Bi.sub.2 Te.sub.3 as well as elemental Bi.

Abstract: A free machining cast steel shape containing bismuth which functions as a liquid metal embrittler. The ability of the bismuth to function as a liquid metal embrittler is enhanced by restricting the total amount of ingredients which lower the wetting ability of the bismuth to less than the bismuth content and by controlling the amount of strengthening elements added to the steel.

Abstract: Lead, bismuth and tellurium and/or sulfur are added to steel, to increase the machinability of the steel, in an addition alloy consisting essentially of 5-40 parts lead, 5-40 parts bismuth, up to 6 parts tellurium and up to 25 parts sulfur. The alloy contains at least one of the group tellurium and sulfur, and the alloy has a melting point of at least about 400.degree. C. (752.degree. F.).

Abstract: A steel billet is produced having free machining properties and substantially devoid of surface-cracking in the as-deformed condition and without surface conditioning. The steel contains bismuth and tellurium and may contain lead but in a smaller amount than is conventional in leaded, free machining steels. The billet was hot deformed at a temperature above about 920.degree. C. (1700.degree. F.) and below 1150.degree. C. (2100.degree. F.). The steel contains inclusions of MnTe and Bi.sub.2 Te.sub.3 as well as elemental Bi.

Abstract: Particulized coal is subjected to a series of processing operations to produce a formed coke product. Among the operations are a single stage heating process comprising both carbonizing and calcining operations or, alternatively, a heating process in which carbonizing alone or carbonizing and calcining are conducted in separate stages. At least the carbonizing operation is conducted in the absence of extraneous gas so that the valuable by-product gases driven off from the coal during heating are unadulterated; and the carbonizing operation is conducted with gradual heating in the single stage heating process.

Abstract: Coal fines are separated from a mixture containing liquid and coal fines in an apparatus comprising a combination surge tank and flotation tank employing air bubbles to urge the coal fines toward the overflow from the flotation tank.

Abstract: Coal particles are heated and further particulized at a preheat stage employing a preheat gas. Some of the finer coal particles are puffed up by the preheating step. Most of the preheated coal particles are separated from the preheat gas, but some of the finer coal particles remain with the preheat gas. The coal particles separated from the preheat gas are oiled and eventually transported by a carrier gas through a pipeline into a coke oven. The preheat gas and the finer coal particles remaining therewith are separated from each other utilizing a wet scrubber at which the finer coal particles undergo flocculation. Oil vapor vented from the coal particles headed for the coke oven is directed to the wet scrubber to aid in the flocculating step. The flocculated coal particles are separated from the scrubber liquid in a flotation cell. The overflow from the flotation cell is filtered, and the filter cake comprising coal particles is employed as a fuel.