Abstract: Described is the process for forming a hardenable mixture of a coal ash comprising free CaO and free CaSO.sub.4.0 H.sub.2 O.In order to remove all free CaO the coal ash is mixed with a fly-ash comprising essentially no free CaO and no free CaSO.sub.4.0 H.sub.2 O and water and subsequently subjected to a heat treatment.By removal of free CaO it is found that the strength of hardened granules formed from such ash mixture does not deteriorate as is the case from granules formed with a coal ash comprising free CaO.Also a process for forming hardened granules and a building component formed with use of a hardenable mixture according to the invention are described.

Abstract: Described is the process for forming a hardenable mixture of a coal ash comprising free CaO and free CaSO.sub.4 .OH.sub.2 O.In order to remove all free CaO the coal ash is mixed with a fly-ash comprising essentially no free CaO and no free CaSO.sub.4.OH.sub.2 O and water and subsequently subjected to a heat treatment.by removal of free CaO it is found that the strength of hardened granules formed from such as mixture does not deteriorate as is the case form granules formed with a coal ash comprising free CaO.Also a process for forming hardened granules and a building component formed with use of a hardenable mixture according to the invention are described.

Abstract: A process for manufacturing hardened granules produced by mixing at least fly ash obtained from combustion of a material selected from a coal product and lignite, a binder and water, forming granules of said mixture, hardening said granules in an embedding material at a temperature between 85.degree. and 212.degree. F. by applying heat and separating the hardened granules from the embedding material, said embedding material being used for forming new granules, including the step of embedding the non hardened granules after granulation in a hardening reactor in a fine grained material with a water absorption capacity of at least 8% and being free from a compound generating heat by contacting water, and supplying heat to the mixture of granules and embedding material in said hardening reactor by introducing steam into the mixture of granules and embedding material as present in the hardening reactor to raise and maintain the temperature at a value comprised between 85.degree. F. and 212.degree. F.

Abstract: The present process involves an improvement in the hydrometallurgical recovery of metal values from metal bearing sources such as ores and the like. The metal values are obtained by subjecting a metal bearing source to a reductive roast at an elevated temperature followed by cooling the reduced metal bearing source, extracting the cooled source and recovering the resultant metal values. An improvement in this process is effected by adding a compound containing a metal of Group IA or IIA of the Periodic Table to the source before subjecting the source to the reductive roast. Following the roast the ore is quenched in an aqueous solution and thereafter subjected to an extraction step.