Abstract: The present invention relates to a process for decreasing the content of organic-chemical substances in waste water by chemical oxidation, preferably in the presence of chlorine, and optionally additional alkaline thermal treatment of the waste water, in which the waste water, which has a COD content (chemical oxygen demand) and is alkaline or is rendered alkaline, is introduced into at least one reactor and is treated at a temperature of more than 15.degree. C. with a chlorine-containing and/or chlorine-releasing chemical substance, the introduction of chlorine taking place in a quantity of more than 1 g chlorine/g COD (relative to the chlorine content of the chlorine-containing and/or chlorine-releasing chemical substance), and a molar ratio of OH.sup.- to chlorine of more than 1.5 and a pH value of the waste water of .gtoreq.5 being maintained or set, and the resulting chlorine-treated, hypochlorite-containing waste water is subjected to a reaction time of more than 0.

Abstract: A process for preparation of polyglycerol is provided, comprising the steps of (a) reacting glycerol or diglycerol with hydrogen chloride at between about 340.degree. K. and about 410.degree. K. to yield a mixture that comprises an .alpha.-monochlorohydrin of glycerol or an .alpha.-monochlorohydrin of diglycerol, (b) mixing the .alpha.-monochlorohydrins and an alkali metal glycerolate or an alkali metal diglycerolate at a temperature of between about 320.degree. K. and 410.degree. K. to yield a mixture of alkali metal chloride and glycerol and/or diglycerol and polyglyerol, (c) separating the alkali metal chloride from the glycerols and (d) separating the polyglycerol from glycerol and/or diglycerol.

Abstract: Connection means for connecting two components such as conveyor channel sections or guide sections includes an elongate connector. The connector is insertible into laterally-open recesses formed in coupling elements attached to the two components. The laterally-open recesses define an elongate aperture which is slightly longer than the connector so that the connector is received within the aperture with a predetermined amount of axial play. A retaining device prevents axial movement of the connector within the aperture by filling up the space available for said predetermined amount of axial play. The retaining device comprises a C-shaped resilient member and a wedge-shaped member. The resilient member is made of corrosion-resistant, resiliently-deformable plastics material, and the wedge-shaped member is made of metal. The wedge-shaped member can be driven into the resilient member to expand the resilient member against the walls of said space, thereby fixing the retaining device in position.

Abstract: A machine frame for a scraper-chain conveyor employs a housing or `plough box` containing a chain wheel for driving a haulage chain. A stripper device is provided in the housing to separate the chain from the chain wheel. The stripper device is composed of a one-piece shaped element with an arcuate blade projecting into the chain wheel. The element is fitted to a mounting flange of the housing with a single upstanding bolt-and-nut and a separate complementary locking member. The element, the locking member and the flange have shape-locking interengaging projections and recesses. The device can be positionally inverted.

Abstract: A drive frame for a scraper-chain conveyor comprises a pair of generally parallel side plates. A pair of aligned bearing bushes rotatably support a drive shaft of a chain drum. The bearing bushes are mounted in apertures in the side plates. The bearing bushes are welded to their respective side plates, thereby strengthening the drive frame.

Abstract: A mineral mining installation comprises a longwall conveyor, a plough movable to and fro along a guide fixed to the face side of the longwall conveyor, and a drive station at one end of the longwall conveyor. The drive station includes a drive frame supporting drive means for driving the longwall conveyor. A support beam is provided at the goaf side of the drive station. The support beam extends substantially parallel to the drive frame. A floor plate extends beneath the drive frame. The goaf-side end portion of the floor plate is supported on the support beam by means of a lifting device, whereby the goaf-side end portion of the floor plate can be moved up and down relative to the support beam by the lifting device.

Abstract: Mining apparatus comprises a longwall conveyor and tensioning means for tensioning the conveyor in its longitudinal direction. The tensioning means is constituted by a plurality of hydraulic tensioning rams, each of which is mounted, in use, by means of pivot joints at each end thereof directly between the conveyor and a respective roof support unit of a roof support assembly. Each tensioning ram extends at an acute angle to the longitudinal axis of the conveyor. The tensioning rams are positioned in two groups, one in each end zone of the conveyor.

Abstract: A mineral mining installation employs a scraper-chain conveyor with a guide at the mineral-face side supporting a main machine, such as a plough, driven back-and-forth along a mineral face by a chain disposed at the mineral-face side of the conveyor. A further chain drive is arranged at the opposite side of the conveyor and is drivably coupled to an arm projecting over the conveyor and connecting with a further plough body. The further plough body is either supported together with the arm on further guides so that it can be driven back and forth along the face above the main machine or else the further plough body is supported directly on the main machine with its arm guided at the opposite side of the conveyor. Releasable coupling devices enable the further plough body to be connected to the main machine.