Abstract: A cement composition to be combined with water comprises high alumina cement, beta anhydrite, aluminium sulphate, a source of free lime and a reactive filler, eg. blast furnace slag to form a rapid setting and hardening durable material.

Abstract: Coal fines are agglomerated by mixing together the coal fines, a phenol-formaldehyde resole resin in alkaline aqueous solution and a curing agent for the resin comprising one or more esters selected from esters of polyhydric alcohols, carbonate esters and lactones, forming the resulting mixture into agglomerates and drying and curing the agglomerates. A small proportion of a thermoplastics material such as polyvinyl alcohol or an acrylic polymer may be included to improve the surface hardness of the agglomerates, and a small proportion of a material which will improve the coking property and hot strength of the agglomerates, for example finely ground coking coal or bitumen when the coal fines are anthracite fines, may also be included.

Abstract: A cement composition which when mixed with water hydrates to form a hardened cement containing ettringite comprises a high alumina cement, beta-anhydrite and calcium oxide and/or calcium hydroxide. The composition may also contain a calcium sulphate which is partially water soluble, an alkali metal sulphate, an accelerator for the high alumina cement such as lithium carbonate, and/or a bentonite clay. The composition is particularly suitable for filling cavities in mines.

Abstract: A substantially dry powder composition which when mixed with water forms a gel comprises a swelling clay, a sodium silicate having a silica to soda weight ratio of about 2.65:1 or below and an inorganic gelling agent for the sodium silicate which gelling agent does not introduce ions which significantly lower the gelling capacity of the clay.The composition is particularly suitable for use in coal mines as an anti-combustion material.