Abstract: A tubular burner for industrial furnaces is capable of achieving a good mixing of combustion gas and fuel. This burner contains an end section projecting into a combustion zone supplied with secondary combustion air, and several separate annular feed ducts for combustion gas and fuel bounded by tubular walls arranged coaxially one inside the other, individual nozzles being arranged in approximately annular distribution in the end wall of the combustion gas feed duct facing into the combustion zone. To achieve a good mixing of combustion gas/combustion air and fuel, at least one outer annular feed duct is constructed essentially as fuel feed duct, whilst the combustion gas feed duct equipped with individual nozzles is arranged radially inside this fuel feed duct.

Abstract: The invention relates to an apparatus for treatment of material, especially for thermal and/or chemical treatment, having an ascending pipeline branch, a diversion chamber and at least one descending pipeline branch. In the diversion chamber there is provided a deflecting wall that is oriented substantially transversely to the direction of flow of the material entering the diversion chamber via the ascending pipeline branch.

Abstract: A method and apparatus for heat treatment of fine-grained material. In order to reduce the nitrogen oxide content of the exhaust gas from the combustion zone, a region of the calcination zone is operated under reducing conditions and ammonia-containing additives are introduced into the calcination zone. In this case, at least the predominant proportion of the ammonia-containing additives is only added in a region of the calcination zone in which the secondary combustion of the combustion products which are formed in the section operated under reducing conditions but are not completely reacted out is largely concluded.

Abstract: The invention relates to a roll mill with two rolls which are rotatably mounted in a machine frame and have an outer wear protection casing. In order to facilitate a particularly simple and rapid replacement of the wear protection casings on the rolls, both rolls are mounted only at one end in the machine frame.

Abstract: In the method according to the invention for reducing volatile pollutants in the exhaust gases of a heat exchanger system for heating of cement raw meal or the like, partially preheated raw meal is heated to a temperature for release of the pollutants contained therein. In order to be able to achieve this with a reliable mode of operation and with relatively low investment costs, partially preheated raw meal is drawn off from an upper preheater stage and is mixed together in a mixing zone with a fraction of raw meal which is already highly heated and of such a size that the raw meal mixture which is obtained is set to a mixing temperature which releases the pollutants and as a result at least volatile sulphur oxides are incorporated into the raw meal mixture, whilst carbon monoxide formed in the course of this is led off by means of a carrier gas.

Abstract: A method of forming a grate plate for installation as part of a grate assembly in which free flowing abrasive material is supported for movement along a path while treatment gas flows upwardly through such material. The grate plate includes a relatively thin carrier plate modified to present a highly wear resistant upper surface, the carrier plate having slots formed therein through which treatment gas flows for passage through the material. The method is one which is economical even though the carrier plate itself is formed from relatively expensive material.

Abstract: The invention relates to a method of producing a grinding roll in which a roll tire made from a highly wear-resistant bainitic cast material is applied to the basic roll body. In order to create a roll tire with particularly high reliability against fractures and with relatively high wear resistance and compression strength, the roll tire is produced from a ductile bainitic spheroidal graphite cast material having a breaking elongation of approximately 0.1 to 2.5% and a compression strength of approximately 1,000 to 1,800 Mpa.

Abstract: The invention relates to the production of cement clinker from cement raw material using a preheating zone, a calcination zone, a heating zone in which the calcined material is further heated whilst avoiding the formation of a molten phase, as well as a clinker burning zone and cooling zone from which part-quantities of the hot exhaust air are delivered as combustion air together with proportions of fuel to the clinker burning zone, the heating zone and the calcination zone. A reliable further heating while avoiding incrustations is achieved in the heating zone by constructing this zone in the manner of a flue stream reactor to which calcined material, fuel and combustion air are delivered in the lower end region of a rising first treatment zone at one point in each case and from which the heated material is precipitated essentially by the effect of gravity overlaid with centrifugal action.

Abstract: The invention relates to a method of recovering precious metals from oxidic or refractory or semi-refractory ore material containing precious metal. This recovery of precious metal takes place with optimal comminution work and with more efficient and more reliable leaching also of non-oxidic ore material in such a way that the ore material is subjected to material bed comminution in the grinding gap between two rollers which are pressed against one another under high pressure and revolve in opposite directions and afterwards the comminuted ore material is preferably leached using a stirring movement in a container.

Abstract: A method and apparatus for comminuting granular mill feed material wherein the material is delivered in a stream to a gap between two rotary grinding tracks which confront one another, one of which is positioned at a small angle to the other so that in response to relative rotation of such tracks the width of the gap decreases to a minimum at an initial rate of at least 1 m/s. At the minimum width of the gap the material is subjected to comminuting pressure greater than 50 MPa.

Abstract: A grate plate construction for installation as part of a grate assembly in which free flowing material is supported for movement along a path while treatment gas flows upwardly through such material. The construction has a relatively thin carrier plate having a highly wear resistant upper surface mounted in a supporting frame having ribs and webs which form with the carrier plate channels through which treatment gas flows for passage through the material via slots formed in the carrier plate by a high-energy process. The construction is economical even though the carrier plate itself is formed from relatively expensive material.

Abstract: The invention relates to the heat treatment of fine-grained material which is first of all preheated in a multi-stage cyclone preheater, then further heated in a calcination zone, next finally burnt in a kiln and then cooled. Preheated material and tertiary air are delivered to the reaction chamber of the calcination zone in order to maintain therein a reducing atmosphere for reduction of the NO.sub.X content in the kiln exhaust gases. For the purpose of good adjustability of the reaction temperature in the reaction chamber and for the purpose of a space-saving construction, the preheated material from the second-lowest preheating stage as well as tertiary air are introduced at the bottom into the reaction chamber and an adjustable part-quantity of the preheated material from the third-lowest preheating stage is introduced into an upper region of the calcination zone.

Abstract: A grinding roll for use in a material bed roll mill for the comminution of brittle material has a cylindrical body in the periphery of which are alternating grooves and lands. To the exterior of each land is secured a wear strip. The grooves of the confronting rolls may be directly opposite one another or the grooves may be offset axially so that the grooves in one roll confront a land of the opposite roll.

Abstract: In this method of comminution according to the invention, pre-comminuted ore material is subjected to material bed comminution in a material bed roll mill. In order to achieve optimal comminution even of very different ore materials with a high throughput the ore material is pre-comminuted in an autogenous mill, whereupon at least fractions of fine material are separated out of the pre-comminuted material before the rest of the material is further comminuted in the material bed comminution.

Abstract: A method and apparatus for preventing the accumulation of fines and the resulting formation of snowmen in a clinker cooler by applying short duration blasts of high pressure, high velocity air from openings in the cooler inlet grate. The cleaning air can be selectively supplied to a portion or portions of the cooler inlet grate. Monitoring may be provided to aid in the selective application of the cleaning air.

Abstract: The reciprocating grate according to the invention for the treatment of bulk material, particularly for cooling hot material by means of gases, comprises a plurality of rows of grate plates disposed behind one another in the longitudinal direction of the grate, of which at least some are moveable to and fro relative to the others, wherein the grate plates of rows of adjacent grate plates overlap each other somewhat like scales. In order that the wear between grate plates moving relative to one another and the requirement for confining air between these grate plates can be kept relatively low, in at least one longitudinal portion of the grate in each case at least two rows of grate plates which are immediately adjacent to one another are jointly movable relative to at least one succeeding row of grate plates.

Abstract: The invention relates to a separator comprising a separator housing with an inlet spiral for separating air which opens tangentially into an annular separating chamber and is divided into a plurality of delivery channels which lie one above the other, as well as a basket-shaped separator rotor disposed centrally and with a vertical axis in the separator housing and a guide vane ring which surrounds the latter with a radial clearance. In order that this separator on the one hand has a high effectiveness of separation between oversize material and fine material and on the other hand facilitates a sufficiently broad grain size distribution of the fine material, the overall shape of the separator rotor is that of a cone which tapers downwards.

Abstract: The invention relates to the preparation of a material mixture consisting of a plurality of mineral raw material components which are delivered individually proportioned, are ground and homogenised, wherein samples are periodically analysed and determined ACTUAL values are compared with predetermined DESIRED values in order if appropriate to carry out corrective control interventions on the proportioning of raw material components by way of a laboratory computer. In relatively short time periods evaluations of the material samples and re-homogenisation of the ground mixture can be carried out very reliably with relatively low expenditure on construction if the material samples are analysed on the spot by means of a rapid analysis arrangement and the determined ACTUAL values from this analysis are passed to the laboratory computer, the homogenisation being carried out in a mixing zone with relatively small receiving capacity which is separated from the storage zone.

Abstract: A double layer cooler for particulate material has a conveyor to which separate streams of such material are delivered at spaced intervals to form lower and upper layers of material on the conveyor. As the layers move toward the discharge end of the conveyor a coolant passes upwardly through the layers. At the discharge end of the conveyor the material of the lower layer is discharged, whereas the material of the upper layer passes over a stationary quantity of material to a crusher in which the upper layer material is crushed. From the crusher material is returned to that stream which forms the lower layer on the conveyor. The lower layer of material thus is precooled and comminuted.

Abstract: The invention relates to a method as well as to apparatus for combined grinding of at least two materials of differing grindability, such as clinker and limestone, wherein the material which is more difficult to grind is pre-crushed to a Blaine fineness of grinding of at least 700 cm.sup.2 /g and there-after is further ground together with the other material to produce the finished material.