CN213000524U

CN213000524U - Bauxite raw pulp grinding system

Info

Publication number: CN213000524U
Application number: CN202021500065.XU
Authority: CN
Inventors: 李果; 郭智峰; 张勇
Original assignee: Chifeng Qihui Aluminum Development Co ltd
Current assignee: Chifeng Qihui Aluminum Development Co ltd
Priority date: 2020-07-27
Filing date: 2020-07-27
Publication date: 2021-04-20
Anticipated expiration: 2030-07-27

Abstract

The utility model relates to a raw ore pulp production system of bauxite. A bauxite raw ore pulp grinding system is characterized in that a bauxite raw ore storage device is input and communicated with a mill feeding hole, a mill discharging hole is communicated with an intermediate tank, an intermediate tank outlet pipeline is communicated with a screening machine through an intermediate pump for feeding, undersize materials of the screening machine are input into a qualified ore pulp tank, and oversize materials are input into the mill feeding hole; the screen surface of the screening machine is welded on the side plates at intervals by stainless steel screen bars, and at least two levels of the adjacent screen bars form splayed reducing screen seams from top to bottom. The utility model discloses classification efficiency increases substantially, and the qualified ore pulp of sieve machine ejection of compact contains 400 + 800g/l admittedly, reduces the sand return volume than traditional grading equipment by a wide margin, alleviates mill circulation load, and the former ore pulp of mill ejection of compact contains 800 + 1200g/l admittedly, and the former ore pulp classification efficiency of mill ejection of compact improves 20%, and this system can increase substantially ball mill productivity 20%, reduces the supporting quantity of mill and has cancelled the rotary screen simultaneously, reduces investment cost.

Description

Bauxite raw pulp grinding system

Technical Field

The utility model belongs to the technical field of aluminium oxide, concretely relates to raw ore pulp production system of bauxite.

Background

The existing bauxite raw pulp system in the alumina industry is the first process of alumina production. As shown in figure 1, the system is simple and practical at present, bauxite, lime and circulating mother liquor enter a mill from a feed end of the mill according to a certain proportion, ore pulp discharged by the mill enters an intermediate tank and is sent to a hydrocyclone by an intermediate pump, overflow materials of the hydrocyclone enter a rotary screen to isolate coarse slag and then enter a qualified ore pulp tank, and underflow of the hydrocyclone returns to the mill to be continuously milled. The configuration of the suitable raw ore pulp grading equipment can greatly improve the grinding capacity of the raw ore pulp and reduce the energy consumption.

The raw ore pulp discharged from a mill in the traditional bauxite raw ore pulp grinding and grading process is generally graded by a hydrocyclone or a spiral classifier. The hydrocyclone is to screw the raw ore pulp discharged from the ball mill into a cylinder in a tangential direction by a pump or a height difference at a certain pressure and flow rate, and then the ore pulp rotates along the cylinder wall at a high speed to generate centrifugal force. The classification is performed by the action of centrifugal force and gravity. The hydraulic cyclone has the disadvantages that the cylinder body, the sand setting nozzle, the ore feeding pipe and other parts of the hydraulic cyclone are quickly abraded, and the power loss caused by abrasion is large. Secondly, the pressure, concentration and granularity of ore feeding can greatly influence the grading effect. The spiral classifier is based on the principle that the solid particles in the raw ore pulp discharged by the ball mill have different sizes and specific gravities, so that the fine ore particles float in the solution and overflow, and the coarse ore particles sink at the bottom of the tank. The mechanical classification is carried out by pushing the spiral to the upper part for discharging. The disadvantage is that the equipment occupies a large area. And secondly, the helical blade and the thrust bearing at the lower end of the helix are easy to wear and inconvenient to overhaul. In addition to the above disadvantages, the two types of classification equipment have the phenomena of thin underflow clamp and thick overflow running, which not only causes low efficiency and low yield of the grinding process of the raw bauxite pulp, but also causes equipment failure of the next process due to the thick running phenomenon. In addition, when the two grading devices are adopted, a rotary screen is required to be arranged in the system, and the rotary screen is used for performing coarse separation treatment on overflow of the hydrocyclone or the spiral classifier, so that impurities such as rubber, plastics and the like in the process flow are prevented from entering qualified ore pulp.

In recent years, there is a vibrating screen processing in the ore production industry, for example, chinese patent CN 202010336502.7 discloses an ore vibrating screen, "the length, width and thickness of the base plate are 1750mm, 125mm and 12mm respectively, and the number of the screen bars is 15, the length of the screen bars is 900mm, the upper width is 40mm, the lower width is 38mm, the thickness is 40mm, and the screen bar interval is 80 mm", which is used for common screening effect; however, the method of classifying the raw ore pulp discharged from the mill by screening is not successful until now, and the main problems are three aspects: firstly, the screen cloth rate of passing through the sieve is low, and the qualified former ore pulp of aluminium oxide requires the granularity to be less than or equal to 1.2mm, and sieve machine sieve clearance or sieve mesh are very little and material viscosity is great, and the material gets into behind the sifter, blocks up the sifter gradually because of the effect of viscidity and material surface tension, leads to unable grading. Secondly, the temperature of the raw ore pulp discharged by the bauxite mill is more than or equal to 80 ℃, and a polyurethane sieve plate or a steel wire woven sieve is adopted in the common sieve machine during fine-grained wet screening. The service life of the polyurethane sieve plate can be greatly reduced when the material temperature is more than or equal to 75 ℃, the gaps of the sieve plate or sieve pores can also deform, and the material grading effect is poor. The wire diameter of the steel wire woven screen is small (the screen hole is 1.2 mm), and the steel wire woven screen is not wear-resistant and impact-resistant. And thirdly, the raw ore pulp discharged by the bauxite grinder is a high-alkalinity material, and the polyurethane sieve plate and the steel wire woven sieve plate are corroded to greatly reduce the service life. The life was less than 1 month under test.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the problem that the ore grinding process flow of the prior bauxite raw ore pulp is long, the grading efficiency is low and the equipment investment is large, providing a bauxite raw ore pulp ore grinding system, adopting the ore grinding system of mill ore grinding + screening separation, improving the productivity and the grading efficiency of the mill, reaching the purposes of increasing production and reducing consumption.

The utility model discloses a solve the technical scheme that above-mentioned problem adopted and be:

a bauxite raw ore pulp grinding system comprises a grinding machine and is characterized in that a bauxite raw ore storage device is input and communicated with a feeding hole of the grinding machine, a discharging hole of the grinding machine is communicated with an intermediate tank, an outlet pipeline of the intermediate tank is communicated with a screening machine through an intermediate pump for feeding, undersize materials of the screening machine are input into a qualified ore pulp tank, and oversize materials are input into the feeding hole of the grinding machine; the screen surface of the screening machine is welded on the side plates at intervals by stainless steel screen bars, and adjacent screen bars form at least two-stage splayed reducing screen seams from top to bottom.

The cross section of the screen bar is in a shape of a trapezoid connected with a triangle.

The screening machine adopts a fixed screen or a vibrating screen.

The screen surface of the screen machine is arc-shaped.

The minimum gap size of the reducing screen seam of the screening machine is less than or equal to 1.2 mm.

The thickness of the sieve plate is 3-10 mm.

The mill adopts a ball mill or a rod mill.

The utility model discloses compare with the same kind and have apparent effect:

1. the system adopts a mill and a screening machine for classification, the classification adopts a screening form, the system belongs to strict physical classification, the screen seam design of the screening machine is ingenious, at least two stages of screen seams with variable diameters are in a shape like a Chinese character 'ba' from top to bottom, in the work, when raw bauxite pulp passes through the screen surface, the screen bars can generate a cutting effect on the surface of a material, the surface tension of the material is damaged, the classification efficiency is improved, the material can rapidly pass through the screen seams under the action of the gravity of the combined material through the tension change of at least two stages, the classification qualification rate is 100%, and the blockage is effectively avoided. In addition, the thickness of the sieve plate can be adjusted from 3 mm to 10mm, the sieve plate is made of stainless steel, and the sieve plate is wear-resistant and corrosion-resistant, so that the problem that a common sieve machine is not suitable for bauxite is solved.

2. The use condition is wide, and the core equipment sieve machine in the grading process can feed materials under normal pressure or pressure.

3. The grading efficiency is greatly improved, the solid content of the qualified ore pulp discharged by the screening machine is improved to 800g/l of 400-plus-material from less than 380g/l, the sand return amount is greatly reduced compared with the traditional grading equipment, the circulating load of the mill is reduced, the solid content of the raw ore pulp discharged by the mill is improved to 1200g/l of 800-plus-material from less than 800g/l, the grading efficiency of the raw ore pulp discharged by the mill is improved by 20%, the consumption of the mill is reduced, the system can greatly improve the productivity of the ball mill by 20%, and the purposes of yield improvement and consumption reduction.

4. Compared with the traditional bauxite raw pulp grinding system, the grinding machine matching quantity is reduced, the rotary screen is cancelled, the system investment cost is saved, and the system flow is simplified.

Drawings

Fig. 1 is a schematic diagram of a conventional bauxite raw ore pulp grinding system.

Fig. 2 is the schematic diagram of the bauxite raw ore pulp grinding system of the utility model.

Fig. 3 is a schematic view of the structure of the sieving machine of the present invention.

Figure 4 is the screen plate part section view of the screen machine of the utility model.

In the figure: 1. the device comprises a hydraulic cyclone 2, a mill 3, a middle groove 4, a middle pump 5, a rotary screen 6, a qualified slurry groove 7, a screening machine 8, a side plate 9, a box-type vibration exciter 10, a main beam 11, a screening plate 12, an upper cross beam, a 13 lower cross beam 14, a stainless steel screening strip 15, a screen slot 16, a welding point 17 and a support strip.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The bauxite raw pulp grinding system shown in fig. 2 comprises a grinding machine 2, wherein a bauxite raw pulp storage device is input and communicated with a feeding hole of the grinding machine 2, a discharging hole of the grinding machine 2 is communicated with an intermediate tank 3, an outlet pipeline of the intermediate tank 3 is communicated with a feeding hole of a screening machine 7 through an intermediate pump 4, undersize materials of the screening machine 7 are input into a qualified pulp tank, and oversize materials are input into a feeding hole of the grinding machine 2; the screen surface 11 of the screening machine 7 is welded on the side plate 8 at intervals by stainless steel screen bars 14, at least two levels of variable diameter screen gaps 15 in a splayed shape from top to bottom are formed by adjacent stainless steel screen bars 14, the minimum gap size of the variable diameter screen gaps is less than or equal to 1.2mm, and the screening granularity requirement is met.

As shown in figure 3, the sieving machine 7 can adopt a vibrating sieve with an arc-shaped sieving surface 11, the upper part of a side plate of the sieving machine is provided with an upper cross beam 12, the bottom of the side plate of the sieving machine is provided with a lower cross beam 13, a box-type vibration exciter 9 is arranged on a main beam 10, the cross section of the stainless steel sieve bar is in a trapezoidal connecting triangular shape as shown in figure 4, the bottom end of the stainless steel sieve bar is welded with a support bar, the bottom end is a welding point 16, and the support bar.

The screen machine may also employ a fixed screen.

The thickness of the sieve plate is designed to be 3-10mm according to the material handling capacity and the specification of the sieving machine, and the larger the thickness is, the two-stage or three-stage sieve slots 15 with the splayed reducing diameters formed by adjacent stainless steel sieve bars 14 from top to bottom can be designed.

The mill adopts a ball mill or a rod mill.

Use a newly-built annual product 2600Kt aluminium oxide enterprise as an example, adopt the utility model discloses a classification technology, bauxite, lime, circulation mother liquor get into by the mill feed end according to a certain proportion and grind, groove in the middle of mill ejection of compact ore pulp gets into, via middle pump sending to screen (ing) machine again, qualified ore pulp groove is gone into to the screen (ing) machine undersize material, when the former ore pulp of mill ejection of compact was through the sifting surface, the screen cut that the grating formed had multistage segmentation effect to the material, can destroy material surface tension, the material can flow away rapidly after passing through the sifting surface, can not block up the screen cut. The sieve plate is made of stainless steel materials, so that the sieve plate is wear-resistant, corrosion-resistant and long in service life; the oversize material returns to the mill and continues to be ground, the sand return amount of the screening machine is only half of that of the hydraulic cyclone or the spiral classifier, the circulating load of the ball mill is greatly reduced, and the productivity is improved by 20%. 4 billiard ball mills needing to be configured by adopting the hydrocyclone classification process, and 3 ball mills with the same specification can meet the production requirement by adopting the classification process. 1, the billiard ball grinder is saved, a plurality of corresponding equipment facilities are arranged, a rotary screen is omitted, and the investment and the operating cost are greatly reduced by 25 percent.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that other equivalent modifications can be made by those skilled in the art in light of the teachings of the present invention, and all such modifications can be made as are within the scope of the present invention.

Claims

1. A bauxite raw ore pulp grinding system comprises a grinding machine and is characterized in that a bauxite raw ore storage device is input and communicated with a feeding hole of the grinding machine, a discharging hole of the grinding machine is communicated with an intermediate tank, an outlet pipeline of the intermediate tank is communicated with a screening machine through an intermediate pump for feeding, undersize materials of the screening machine are input into a qualified ore pulp tank, and oversize materials are input into the feeding hole of the grinding machine; the screen surface of the screening machine is welded on the side plates at intervals by stainless steel screen bars, and adjacent screen bars form at least two-stage splayed reducing screen seams from top to bottom.

2. The bauxite raw ore pulp grinding system according to claim 1, wherein the cross section of the screen bars is in a shape of a trapezoid connected with a triangle.

3. The bauxite raw ore pulp grinding system according to claim 1, wherein the screening machine is a fixed screen or a vibrating screen.

4. The bauxite raw pulp grinding system according to any one of claims 1 to 3, wherein the screening surface of the screening machine is curved.

5. The bauxite raw pulp grinding system according to any one of claims 1 to 3, wherein the minimum size of the reducing screen slot of the screening machine is less than or equal to 1.2 mm.

6. The bauxite raw pulp grinding system according to any one of claims 1 to 3, wherein the thickness of a screen plate of the screening machine is 3 to 10 mm.

7. The bauxite raw pulp grinding system according to any one of claims 1 to 3, wherein the grinding machine is a ball mill or a rod mill.