Abstract: An image (100) of particulate material, such as an X-ray image of coal, is captured and processed to determine a parameter of the material, such as particle density or particle size distribution. The performance or efficiency of a processing system, such as a dense medium separator, can be evaluated by determining parameters of the material before entry to and after exit from the processing system. The parameter is determined by comparing image characteristics (relating to statistical features), to a predetermined set of image characteristics. If the image (100) is obtained by transmission of radiation through the material, accuracy can be improved by measuring the thickness of the material.

Abstract: An image (100) of particulate material, such as an X-ray image of coal, is captured and processed to determine a parameter of the material, such as particle density or particle size distribution. The performance or efficiency of a processing system, such as a dense medium separator, can be evaluated by determining parameters of the material before entry to and after exit from the processing system. The parameter is determined by comparing image characteristics (relating to statistical features), to a predetermined set of image characteristics. If the image (100) is obtained by transmission of radiation through the material, accuracy can be improved by measuring the thickness of the material.

Abstract: An image (100) of particulate material, such as an X-ray image of coal, is captured and processed to determine a parameter of the material, such as particle density or particle size distribution. The performance or efficiency of a processing system, such as a dense medium separator, can be evaluated by determining parameters of the material before entry to and after exit from the processing system. The parameter is determined by comparing image characteristics (relating to statistical features or the like of the material), to a predetermined set of image characteristics. If the image (100) is obtained by transmission of radiation through the material, accuracy can be improved by measuring the thickness of the material.

Abstract: A method and apparatus for processing particulate material such as coal, and also for measuring the efficiency of separation of the coal is disclosed. Particulate material is supplied to a separator such as a heavy medium device containing a dense medium (6). A parameter of the device (6) indicative of separation cut point is measured. The parameter may be density of the medium, flow rate of material or pressure of feed as well as medium to coal ratio. Measurements of these parameters are made over a time period and, from the measurements, an induced value indicative of separating efficiency is determined. The induced value provides a measure of separation efficiency and also provides a value which can be compared with a predetermined value so that an alarm can be generated if the value departs from the predetermined value by a predetermined amount.

Abstract: A hydrometallurgical process is provided for producing pigment grade TiO2 from titanium containing solutions. Generally, the solution is an aqueous solution. The process includes hydrolyzing the solution via complete evaporation in well-controlled conditions of temperature to form titanium oxide of well-defined characteristics. The hydrolyzing can be achieved by spray hydrolysis in a spray dryer. After hydrolyzing, the titanium oxide is calcined to transform the titanium oxide to the desired form of titanium dioxide. The titanium dioxide can be either anatase or rutile. Following calcination, the titanium dioxide is milled to provide the desired particle size distribution and then finished.

Abstract: A hydrometallurgical process is provided for producing pigment grade TiO2 from titaniferous mineral ores, and in particular from ilmenite ore. The ore is leached with a hydrochloric acid, preferably a recycled solution at high hydrochloric acid concentration, to form a leachate containing titanium and iron chloride and a residue. The leachate may be filtered to separate the leachate from the residue. The leachate is cooled to a temperature sufficient to form crystals of FeCl2, which are separated from the leachate. The leachate may be subjected to a reduction step to reduce Fe+3 to Fe+2, before crystallizing. The leachate is subjected to a first solvent extraction to form a pregnant strip solution containing titanium and ferric ions and a raffinate containing ferrous ions. This strip solution is subjected to a second solvent extraction to form a second strip solution containing ferric ions and a raffinate containing titanium ions.