RU2079368C1 - Method and apparatus for sorting minerals in respect to their thermophysical properties - Google Patents

Abstract

FIELD: mineral dressing. SUBSTANCE: invention relates to sorting minerals into desired components and reject having different heat-transfer properties. Method includes contact-mode heat transfer from heater through minerals to conveyor belt covered with low-melting substance which melts under mineral exhibiting high heat-transfer effect. Mineral grains are pressed in into the low-melting substance. As conveyor belt, elastic sponged tape is used which, after contact transfer of heat, restores its deformed places. To fasten minerals on the belt, low-melting substance is cooled. Apparatus has vibratory feeder, conveyor belt, emitter in the form of contact heater mounted to be turned against stream, stopping mechanism for desired product, and receiving hoppers for barren rock and desired component. EFFECT: enhanced efficiency of mineral separation. 2 cl, 2 dwg

Description

 The invention relates to the field of mineral processing and can be used to sort minerals into a useful component, for example diamonds and waste rock, having different ability to transfer heat from one body to another.

 A known method of separating minerals by optical properties. According to the known method, the material is classified by size, clean its surface, irradiated with an irradiation source, and heated material is fed onto a paraffin surface / cm. A.S. N 597417, CL B 03 B 3/06, 1976 /.

 A known method of separating minerals by optical properties, which consists in classifying the material by size, cleaning its surface, supplying the material to the irradiation zone with a heat source and then feeding it to the paraffin surface, melting it in places of falling onto it, pieces of material having a sufficient temperature are fixed /cm. a. from. N 152836, cl. B 03 B 13/00, 1961 /.

 The closest to the technical essence of the analogues are a method and device for separating materials according to thermophysical properties, containing a drum screen for separating an unseparable class, 120 kW infrared radiation lamps built into it, a flux monolayer shaper, a conveyor belt coated with a layer of a mixture of polymers of a thermoplastic regenerator polymer, and brushes removal of the concentrate.

 In a drum screen, the starting material is irradiated with infrared radiation. Pieces of rock with a high absorption coefficient of the selective heater. Then the rock is fed by a monolayer flow former to the conveyor belt in a monolayer, where the selectively heated pieces are fixed using polymers and then removed from the tape with a brush / Kravets B.N. Special and combined enrichment methods. M. Nedra, 1986, p. 100-101 /.

 The disadvantage of the data of the method and device is that in the roar the pieces of material are in dynamics and can overlap and the radiated heat flux may not reach the surface of many pieces, which significantly reduces the selectivity.

 If the flow of thermal energy is directed to a monolayer formed on the conveyor, then part of the radiation will fall on sections of the conveyor that are not covered by rock, the plasticizer will melt and pieces of waste rock can be fixed in the melt, which also reduces selectivity.

 The aim of the invention is to increase the accuracy of separation of minerals, increase selectivity and increase the percentage recovery of the useful component.

 The goal is achieved in that in the method for sorting minerals by thermophysical properties, the heat is supplied from the heater through the minerals to the surface of the conveyor belt, the surface of which is impregnated with a fusible substance, is carried out by heat transfer by contact method, while the grains of minerals are pressed into the fusible substance, and as conveyor tapes use an elastic sponge tape, which at the end of contact heat transfer restores deformable areas. Cool the fusible substance to fix the minerals on the tape, and separate the waste rock and the useful component.

 The goal is achieved in that in the device for sorting minerals by thermophysical properties, containing a vibrating feeder, conveyor belt, emitter, useful component cut-off, receiving hoppers of waste rock and useful component, the emitter is made in the form of a contact heater rotating towards the flow, and the conveyor belt is made of sponge and elastic.

 Using a contact method for sorting materials, including introducing a useful component into a spongy elastic tape, fixing and separating minerals and gangue, and using a contact heater rotating towards the flow, and a conveyor belt made of spongy and elastic, increase the accuracy of separation of minerals and productivity separation, ensure reliable thermal contact.

 In FIG. Figure 1 shows how the heat flux incident on minerals such as diamonds, quartz, chrysolites, zircons, and the like is separated. by reflection, absorption, transmittance; in FIG. 2 kinematic diagram of the extraction of useful minerals from the source material stream; in FIG. 3 - the moment of thermal contact, the heater is a mineral elastic sponge conveyor belt.

 The device comprises two drums 1, a conveyor belt made of a spongy elastic material, for example foam rubber, spongy rubber, impregnated with a fusible substance, for example paraffin 2, a contact heater 3, a vibrating feeder 4, a useful component cutter 5, a recoverable mineral piggy bank 6, a waste rock receiver 7.

 The method is as follows.

 On the conveyor belt 2, covered with a layer of fusible material, the feed material 4 is fed with a monolayer vibrating feeder 4, the contact heater 3 is passed through minerals through the fusible layer on the conveyor belt 2, while the grains are pressed into the sponge tape. At the end of the contact heat transfer, the deformable areas on the belt under the minerals are restored due to its elasticity, the useful component is fixed on the conveyor belt 2 with a cooled fusible substance, the useful component is separated from the waste rock, which does not stick to the belt and breaks away from it into the waste rock bin 7, and the useful component of the cutter 3 is separated from the conveyor belt 2 into the hopper 6.

 The device operates as follows.

 The source material, which is subjected to separation, by a monolayer formed by vibrator 4, is fed to a conveyor belt impregnated with fusible substance 2. Moving with the tape, the minerals pass under the contact heater 3, which, rotating towards the ore stream, presses the grains into the sponge tape (Fig. 3) providing reliable thermal contact. After contact heating, the minerals with the tape 2 are on it for a sufficient time, during which the fusible substance cools under the useful component and fixes the grains on the tape.

 With further movement of the material, the waste rock, which does not adhere to the tape, breaks away from it and enters the receiving hopper 7. The useful minerals fixed on the tape, moving further, are cut off by the cutter 5 and sent to the storage tank 6.

 The increase in selectivity is achieved by the fact that a method of heat transfer by direct contact from the heater through a mineral to a fusible material deposited on a conveyor belt, for example, foam rubber, is applied.

 In this case, a difference is realized in the ability of minerals to transfer thermal energy, i.e. a sign of differences in the thermal conductivity of minerals in the ore stream is used.

 So, for example, the thermal conductivity of diamond is λ 500-12000 W / m • K, for related materials l -0.1-2.0 W / m • K, for metals l 300-465 W / m • K.

,
где Q передаваемое количество теплоты, Дж;
A поперечное сечение проводника, м^ч;
t продолжительность процесса, с;
ΔT разность температур на концах проводника, ^oC;
L длина проводника тепла, м;
λ коэффициент теплопроводности материала проводника, Вт/м•К.Based on the ratio:

,
where Q is the transferred amount of heat, J;
A cross section of the conductor, m ^h ;
t process duration, s;
ΔT temperature difference at the ends of the conductor, ^o C;
L is the length of the heat conductor, m;
λ coefficient of thermal conductivity of the material of the conductor, W / m • K.

,
У кварца:

,
Количество теплоты от горячей стенки к холодной у алмаза передается больше, чем у кварца в 250 раз. Следовательно, при таком большом различии в скорости передачи тепла можно с большей селективностью разделять минералы и металлы, например алмазы, золото, платину, серебро.For a given process time, for example 0.1 s, with a temperature difference of 20 ^o C for a diamond of 1 cm ³ in size with a thermal conductivity of 500 W / m • K heat is transferred:

,
At quartz:

,
The amount of heat transferred from the hot wall to the cold in diamond is transferred more than in quartz by 250 times. Therefore, with such a large difference in the rate of heat transfer, it is possible to separate minerals and metals, for example diamonds, gold, platinum, silver, with greater selectivity.

 Thus, in the proposed method, based on contact heating, minerals are separated into useful components with high thermal conductivity, which are fixed on a tape with fusible material and subsequently automatically dumped into a piggy bank and waste rock, which is not fixed on the tape and is easily separated from it.

 Using a method and device for extracting, for example, diamonds from gravity concentrates will allow you to replace complex expensive lapping X-ray luminescent separators, this device is simpler, has greater performance.

 A prototype was made according to this invention, experimental tests were carried out, and static and dynamic characteristics were taken.

 Experimental data showed that with this invention, the extraction of diamonds from the ore stream is 4% higher than that of finishing luminescent separators. The device is easy to manufacture, operating costs are several times lower than that of fluorescent separators, this invention is environmentally friendly.

Claims (2)

 1. A method for sorting minerals by thermophysical properties, including transferring heat from the heater through minerals to a conveyor belt coated with a fusible substance with melting under a mineral with high thermal conductivity of the fusible substance, cooling the fusible substance to fix the minerals on the tape and separating waste rock and useful component, characterized in that heat is supplied from the heater by the contact method, while the grains of minerals are pressed into a low-melting substance, and as a trans porter tape, flexible sponge tape, which at the end of the contact heat transfer restores deformable.  2. A device for sorting minerals by thermophysical properties, including a vibrating feeder, conveyor belt, emitter, cut-off of a useful component, receiving bins of waste rock and a useful component, characterized in that the emitter is made in the form of a contact heater, mounted with the possibility of rotation towards the flow, conveyor the tape is made of spongy and elastic.

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