Abstract: Waste tires are disposed of in a cement-manufacturing or other mineral-burning process by introducing the tires into the hot gas stream at at least one point between the mineral-inlet end of a rotary kiln and the lowermost cyclone of an associated preheater system, e.g. into the gas stream within a precalciner vessel or riser duct, the tires being maintained in contact with the hot gas for a sufficient period to effect at least partial combustion of the tires. As an alternative, the tires may be introduced into a Lepol grate preheater.

Abstract: Waste tires are disposed of in a cement-manufacturing or other mineral-burning process by introducing the tires into the hot gas stream at at least one point between the mineral-inlet end of a rotary kiln and the lowermost cyclone of an associated preheater system, e.g. into the gas stream within a precalciner vessel or riser duct, the tires being maintained in contact with the hot gas for a sufficient period to effect at least partial combustion of the tires. As an alternative, the tires may be introduced into a Lepol grate preheater.

Abstract: A cementitious composition comprises a ground sulfoaluminous clinker, a ground Portland cement clinker (preferably rapid hardening Portland cement clinker), calcium sulfate, aggregate (especially sand and a coarse aggregate such as granite) and metal (e.g. stainless steel) fibers. The composition may also comprise a plasticizer and agents for controlling setting and hardening. The reinforced concrete produced from the compositions is useful in offshore applications, e.g. as a coating for the weld areas between lengths of steel pipe to be laid under water.

Abstract: A settable cementitious composition is produced by mixing a ground mineral composition containing the phase 4CaO.3Al.sub.2 O.sub.3.SO.sub.3, in the presence of water, with a source of alkali metal or alkaline earth metal under alkaline conditions. In the pump packing method of stowing cavities in underground mines, an aqueous slurry of the mineral composition is mixed with a second slurry containing calcium sulfate, lime and, preferably, bentonite, an alkali metal sulfate and a setting and/or hardening accelerator. The components may be provided initially as a dry mixture. A preferred mineral composition comprises at least 15% by weight of 4CaO.3Al.sub.2 O.sub.3.SO.sub.3, less than 1% by weight of free lime, less than 25% by weight of CaO.2Al.sub.2 O.sub.3 and not more than 10% by weight of 12CaO.7Al.sub.2 O.sub.3.

Abstract: An aqueous slurry of mineral particles, for example calcium carbonate and/or calcium hydroxide, has a mineral solids concentration of at least 40% m/m and contains an agent that maintains the slurry at a pumpable viscosity but that acts as a flocculant upon dilution of the slurry. Suitable agents include cationic and amphoteric polyelectrolytes having nitrogen-containing groups, for example polyamines and dimethyl diallyl ammonium chloride polymers. The slurries may contain other components, for example a synthetic hectorite or a dispersing agent such as a polyacrylate, polymethacrylate or polyphosphate. The slurries are useful in papermaking and in the treatment of sewage.

Abstract: An aqueous slurry of mineral particles, for example calcium carbonate and/or calcium hydroxide, has a mineral solids concentration of at least 40% m/m and contains an agent that maintains the slurry at a pumpable viscosity but that acts as a flocculant upon dilution of the slurry. Suitable agents include cationic and amphoteric polyelectrolytes having nitrogen-containing groups, for example polyamines and dimethyl diallyl ammonium chloride polymers. The slurries may contain other components for example a synthetic hectorite or a dispersing agent such as a polyacrylate, polymethacrylate or polyphosphate. The slurries are useful in papermaking and in the treatment of sewage.

Abstract: Particles having different properties (e.g. particulate fly ash and carbon) are separated by moving the particles forwards along a horizontal, gas-permeable electrode plate (1) above which is mounted a second electrode (2) having at least one plate (4) mounted at an acute angle (.alpha.) to the horizontal. Preferably, two plates (4) each extend sideways from a central block (3) of dielectric material. The particles are fluidized, continuously or intermittently, by a gas stream passed upwards through the plate (1), which may be of sintered metal. An alternating electric field is generated between the electrodes (1, 2) by a high voltage AC power source (14). The field lines (16) from each plate (4) curve to the side and impart centrifugal forces to particles charged by friction or conductive induction, which forces separate the lighter, more highly charged particles from the others. The particles may be moved by means of a vibratory transducer (12).

Abstract: Particles having different properties (e.g. particulate fly ash and carbon) are separated by driving the particles by means of a vibratory feeder (12) forwards along a horizontal electrode plate (1) above which is mounted a second electrode (2) having at least one plate (4) mounted at an acute angle (.alpha.) to the horizontal. Preferably, two plates (4) each extend sideways from a central block (3) of dielectric material. An alternating electric field is generated between the electrodes (1, 2) by a high voltage AC power source (14). The potential across each plate (4) varies (in particular, decreases) in the lateral direction, the variation being continuous or stepwise. The field lines (16) from each plate (4) curve to the side and impart centrifugal forces to particles charged by friction or conductive induction, which forces separate lighter, more heavily charged particles from the others. The separated particles are collected in bins (13) arranged around the lower electrode (1).

Abstract: Particles having different properties (e.g. particulate fly ash and carbon) are separated by moving the particles forwards along a horizontal electrode plate (1) above which is mounted a second electrode (2) having two plates (4) each extending sideways from a central block (3) of dielectric material at an acute angle (.alpha.) to the horizontal. An alternating electric field is generated between the electrodes (1, 2) by a high voltage AC power source (14). The field lines (16) from each plate curve to the side and impart centrifugal forces to particles charged by friction or conductive induction, which forces separate lighter, more highly charged particles from the others. The separated particles are collected in bins (13) arranged around the lower electrode (1), which electrode is mounted on a vibratory transducer (12).

Abstract: Filler particles are coated with an adduct of an unsaturated polymer, e.g. polybutadiene, and phosphinic acid groups. The coated filler may be prepared by reacting an unsaturated organic polymer with a phosphorus trihalide and applying the product in the form of a solution or dispersion in an organic solvent to mineral, e.g. calcium carbonate, particles. If liquid, the product may alternatively be applied as such to the mineral particles. In either case, the product so applied is then hydrolyzed in situ in order to form the phosphinic acid groups. The coated filler particles are useful in the reinforcement of elastomers.