RU2187387C1 - Method of dry concentration of kaolin - Google Patents

Abstract

FIELD: dry concentration of metal-ore minerals, mainly kaolin; concentration of table and dolomite, limestone and other non-metal-ore materials. SUBSTANCE: proposed method includes drying, grinding, three-stage separation, deposition and dust accumulation operations. Kaolin fractions are separated by deposition in aspiration air conditioning line and deposition and dust accumulation in waste drying gas treatment line; they are combined in one flow and are directed for grinding operation. EFFECT: increased extraction of kaolin from raw material; reduced power requirements; increased productivity of productivity of production line and material flows. 1 dwg, 1 ex

Description

 The invention relates to a dry process for the enrichment of non-metallic minerals, mainly kaolin, and can be used to enrich talc, dolomite, limestone and other non-metallic materials.

 A known method of dry enrichment of kaolin [Sukhowsk; K. Keramische Zeitschrift, 1983, 35, 2, 75-77], including drying, grinding, separation, precipitation and dust collection, moreover, the separation is carried out in two stages, and the exhaust gases after drying kaolin are subjected to precipitation and dust collection with the return of the deposited part of kaolin for grinding.

 The disadvantage of this method is the loss of part of finely divided kaolin with air discharged into the atmosphere after its purification in the dust collection operation in the exhaust gas cleaning line.

 A known method of dry enrichment of kaolin [Kovalenko V.I., Tikhonov S.A., Izmedenov Yu.A. Enrichment of non-metallic minerals. - M .: Nedra, 1967, p. 211-214], including drying, grinding, separation, precipitation and dust collection, moreover, the exhaust gases after drying kaolin are subjected to deposition and dust collection with the return of the deposited part of kaolin for grinding with the addition of part of the process air after the deposition operation following the separation operation.

 The disadvantage of this method is the increased emission of kaolin with air discharged into the atmosphere after its purification in the dust collection operation in the exhaust gas cleaning line, as well as the irregular composition of the finely dispersed kaolin trapped in this operation, which causes difficulties with the implementation and use of this product.

 There is a method of dry enrichment of kaolin [copyright certificate of the USSR 412164, cl. From 04 to 33/04, to 07 to 9/00, 1974], including drying, grinding, separation, precipitation and dust collection, the separation being carried out in two stages, and the exhaust gases after drying kaolin are subjected to separation, precipitation and dust collection .

 In this case, the pre-purified gases from the drying and grinding operations are mixed, after which the final cleaning of the gas mixture is performed.

 However, in this case, the finest dispersed fractions of kaolin are emitted into the atmosphere, and grinding and separation operations do not provide a good separation of particles, and therefore sand impurities enter the finished product, reducing its grade.

 A known method of dry enrichment of kaolin [USSR author's certificate 988369, class B 07 V 9/00, 1983], including drying, grinding, separation, precipitation and dust collection, moreover, the separation is carried out in one stage, and the exhaust gases after drying kaolin subjected to dust collection in two stages with the return of the trapped kaolin from these gases from the first stage to grinding.

 This method is mainly intended for producing kaolin with high dispersion and is associated with the introduction of an additional grinding operation, therefore, it has limited use due to the increased energy consumption.

 There is a method of dry enrichment of kaolin, selected as a prototype [USSR copyright certificate 1808424, cl. In 07 In 9/00, 1993]], including drying, grinding, three-stage separation, precipitation and dust collection, and the exhaust drying gases are subjected to deposition and dust collection with the direction of the coarse product after the deposition operation for grinding.

 This method has the disadvantage that, due to the irregular composition of the finely dispersed kaolin allocated to the dust collection operations, it is sent for enrichment to the wet enrichment line. If this line is absent, this product can be sent to waste.

 The present invention solves the problem of increasing the extraction of kaolin from raw materials, reducing energy consumption and increasing the productivity of the process line by creating a closed circulation of process air and material flows.

 This problem is solved in that in the method of dry enrichment of kaolin, including drying, grinding, three-stage separation, precipitation and dust collection, kaolin fractions obtained during their deposition from aspiration air and during their deposition and dust collection from exhaust drying gases are combined into a single stream and sent to the grinding operation.

 The combination of kaolin fractions obtained during their deposition from aspiration air and during their deposition and dust collection from exhaust drying gases allows, without increasing the energy intensity of the enrichment process as a whole, to obtain a material with averaged particle size dispersion.

 Combining these fractions into one stream makes it possible to obtain a material stream that can be used for recycling.

 The direction of this flow to the grinding operation in the kaolin enrichment line together with the process air enables additional enrichment at the separation stages, but after additional separation into grinding operations.

 The proposed method is illustrated in the drawing, which shows a diagram of the technology of dry enrichment of kaolin in accordance with the claimed method.

 The method includes the following operations shown in the diagram: drying, grinding, the first, second and third separation stages I, II and III, deposition operations and dust collection operations after separation stage I and separation stage III (not shown), deposition and dust collection lines purification of suction air and in the exhaust gas cleaning line.

 The method is as follows. The kaolin feed is subsequently subjected to processing in the drying, grinding, three-stage separation operations and in the deposition operations corresponding to the first and third stages of separation to obtain commodity fractions of ordinary kaolin.

 The grinding operation is carried out with recirculation of the under-ground material at the entrance of the same operation.

 Sands are isolated in the second separation stage and sent to a bunker or temporary storage warehouse.

 As a result of processing at the stages of dust collection following the operations of deposition of kaolin, as well as dust collection after deposition of kaolin in the suction air purification line, fine fractions of kaolin are obtained as a finished product, which is sent to the packaging.

 The process air purified to sanitary standards after the dust collection operation is emitted into the atmosphere.

 Example. The exhaust gases after drying are fed to the deposition operation, where large particles are deposited, and then to the dust collection operation, where they are cleaned of fine particles of kaolin. Cleaned to sanitary standards exhaust gases are emitted into the atmosphere.

 Kaolin obtained in the deposition and dust collection operations has an irregular dispersed composition and a wide dispersion range, therefore, it cannot be used as a finished product and is sent to the technological process.

 Aspiration air, which also contains kaolin of an irregular composition and with a wide range of dispersion, is subjected to a deposition operation, from which large particles are sent to the technological process, and to dust collection operations, from which fine particles are removed from the process and can be used as a finished fine product that goes to the packaging.

 Thus, large and fine kaolin fractions obtained from precipitation and dust collection operations must be subjected to additional processing due to the noted properties, and taking into account the fact that they also contain foreign particles, which were mainly found in the aspiration process, as well as sand particles, mostly finely divided, the optimal operation is the grinding operation.

 Combined into one material stream, these fractions are fed to the input grinding operation together with dried kaolin.

Claims (1)

 A method of dry enrichment of kaolin, including drying, grinding, three-stage separation, precipitation and dust collection, characterized in that the kaolin fractions obtained during their deposition from aspiration air and during their deposition and dust collection from exhaust drying gases are combined into a single stream and sent to grinding operation.