CN104236279A - Dehydration and drying method and device for scheelite concentrate - Google Patents

Abstract

The invention discloses a method and a device for dehydrating and drying scheelite concentrate, wherein the scheelite concentrate is filtered and dehydrated by a GW type cylindrical external filter (a ceramic filter or a chamber filter press) to obtain the scheelite concentrate with the water content mass ratio of 2-15% (adjustable range), then the scheelite concentrate is statically moved on a polyurethane belt with the rotating speed of 0-1 m/min (adjustable range) by a microwave device generating microwave frequency of 2400-2500MHZ, the scheelite concentrate with the water content mass ratio of 0.07-2% (adjustable range) is obtained by microwave drying, and finally the scheelite concentrate is transported to a packing workshop by a set of conveying device and packed by an automatic packing machine to obtain the final qualified scheelite concentrate product. The invention is a new process which is applied to the dehydration and drying of the scheelite concentrate by using the microwave drying principle for the first time, has low processing cost, clean and environment-friendly operating environment and little metal loss, and has remarkable economic benefit and social benefit.

Description

Dehydration and drying method and device for scheelite concentrate

technical field

The invention relates to a dehydration and drying method of scheelite concentrate, and also relates to a device for realizing the dehydration and drying method of scheelite concentrate.

Background technique

Drying generally refers to the operation process of removing water or other moisture from wet materials. It is one of the earliest production processes mastered by human beings, and it is also one of the important processes in the production of modern mining enterprises. At present, most industries use hot air, gas, steam (superheated steam), electric heating, etc. for heating. The temperature gradient between the heat source and the material is the original driving force for energy transfer. While removing moisture, all materials need to be heated; and the driving force of mass transfer is the gradient of moisture concentration between the inside and the surface of the material. The evaporation of water starts from the surface of the material, and the internal moisture slowly diffuses from the inside to the surface. To speed up the drying rate, a higher external temperature is required to form a temperature gradient. Microwave heating has the advantages of internal heating and selective heating. Since the dielectric constant ε' of water molecules is as high as 70-78, which is much larger than that of general minerals and compounds, during the microwave drying process, water molecules always preferentially absorb a large amount of microwaves, forming a relatively large vapor pressure in a short time, and rapidly escaping from the material. surface, significantly reducing drying handling time. This drying method reduces the overall heating of the material and greatly reduces energy consumption; at the same time, due to the characteristics of internal heating, a temperature gradient from inside to outside is formed in the material, and its direction is the same as that of moisture transmission, which greatly reduces the drying effect. It promotes the mass transfer process of water molecules and improves the drying efficiency. The material is in a static state during the drying process, thereby reducing dust flying and keeping the environment clean and environmentally friendly. Therefore, the microwave drying process has been paid more and more attention and developed rapidly.

Contents of the invention

The first technical problem to be solved by the present invention is to provide a dehydration and drying method for scheelite concentrate with low processing cost, qualified products, clean and environment-friendly working environment, and minimal metal loss.

The second technical problem to be solved by the present invention is to provide a device for realizing the dehydration and drying method of the scheelite concentrate.

In order to solve the first technical problem above, the present invention provides a dehydration and drying method for scheelite concentrate. The scheelite concentrate is filtered through a filter device, and then passed through a cavity of a microwave drying device, and the cloth moves on a belt in a static manner. and dried by microwave.

The scheelite concentrate contains 35% to 80.5% of the WO ₃ grade; the particle size distribution of the scheelite concentrate -200 mesh mass ratio is 55% to 96%; the scheelite concentrate The mass ratio of water is 30%-50%.

It specifically includes the following steps: first, the flotation scheelite concentrate in the scheelite beneficiation plant is filtered by the filter equipment and then transported to the drying workshop; thirdly, the static cloth moves slowly on the belt and is dried by the microwave device that generates microwaves; A set of conveying device, transported to the packaging workshop to pack qualified scheelite concentrate products through automatic packaging machine.

The static cloth thickness of the scheelite concentrate on the belt is 0.5cm-5cm.

The microwave frequency is 2400-2500MHz, and the microwave leakage is less than 1mW/cm ² .

The belt speed is 0m/min～1m/min.

After the flotation scheelite concentrate is filtered and dehydrated by a cylindrical external filter (ceramic filter or chamber filter press), the water content of the scheelite concentrate has a mass ratio of 2% to 15%.

In order to solve the above-mentioned second technical problem, in the device for realizing the dehydration and drying method of scheelite concentrate provided by the present invention, the outlet of the filtering equipment is connected to the inlet of a microwave drying device, and the outlet of the microwave drying device is connected to the conveying device. The inlet and outlet of the conveying device are connected to an automatic baler.

The filter equipment includes: GW type cylindrical external filter filter (ceramic filter or chamber filter press), and the filter vacuum pressure is stable above 0.8 MPa.

The structure of the microwave drying device includes: a material distribution device (double toothed roll), passive support, dehumidification system, suppression system, box support, cleaning window, cooling pipeline, electrical system, microwave cavity, active support and Feeding port and conveying belt.

The conveying device is an air conveying device or a screw conveying device, and the structure of the air conveying device includes: a feed inlet, a suction nozzle, a conveying pipe (lined ceramic pipe), a primary cyclone separator, a silo, a secondary Cyclone separator, fan and outlet.

The process parameters of the microwave drying device are: microwave frequency 2400-2500MHz, 8 groups in total, belt speed 0-1m/min (range adjustable), box temperature less than 45°C, microwave leakage less than 1mW/cm ² .

Belts are polyurethane belts.

The dehydration and drying method and device for scheelite concentrate adopting the above-mentioned technical scheme, after the scheelite concentrate is dehydrated and dried, the qualified product of the scheelite concentrate has a water mass ratio of 0.07%-2%.

Compared with the prior art, the present invention has the following advantages and positive effects:

1. The drying effect is particularly remarkable. It only takes 25 minutes to dry the scheelite concentrate with a moisture content of 2%-15% (adjustable range) to 0.07%-2% (adjustable range).

2. Compared with other drying methods, it saves more energy. The electric energy is converted to microwave and then the concentrate is dried, and about 1 kWh of electric energy removes 0.6t of water.

3. The loss rate of tungsten concentrate is low. According to statistical analysis of data, the drying loss rate of scheelite concentrate is controlled below 0.5%.

4. There is no dust in the production process of this process, which is clean and environmentally friendly to the environment.

Description of drawings

Figure 1 is a schematic diagram of the structure of a cylindrical external filter filter.

Fig. 2 is a front view of the structure of the microwave drying device.

Fig. 3 is a left view of the structure of the microwave drying device.

Fig. 4 is a schematic diagram of the structure of the air conveying device.

Fig. 5 is a schematic diagram of the structure of the automatic packing machine.

Detailed ways

In order to better understand the present invention, the content of the present invention will be further described below in conjunction with the examples, but the present invention is not limited to the following examples, those skilled in the relevant technical field, without departing from the spirit and scope of the present invention, can also Various changes can be made. Therefore, all equivalent technical solutions should also belong to the category of the present invention and should be defined by each claim.

The dehydration and drying method of scheelite concentrate, scheelite concentrate is filtered through a filter device, and then passed through a cavity of a microwave drying device, the static cloth moves on the belt and is dried by microwave.

The scheelite concentrate contains 35% to 80.5% of the WO ₃ grade; the particle size distribution of the scheelite concentrate -200 mesh mass ratio is 55% to 96%; the scheelite concentrate The mass ratio of water is 30%-50%.

It specifically includes the following steps: first, the flotation scheelite concentrate in the scheelite beneficiation plant is filtered by the filter equipment and then transported to the drying workshop; thirdly, the static cloth moves slowly on the belt and is dried by the microwave device that generates microwaves; A set of air conveying device is transported to the packaging workshop to pack qualified scheelite concentrate products through automatic packaging machines.

The static cloth thickness of the scheelite concentrate on the belt is 0.5cm-5cm.

The microwave frequency is 2400-2500MHz, and the microwave leakage is less than 1mW/cm ² .

The belt speed is 0m/min～1m/min.

After the flotation scheelite concentrate is filtered and dehydrated by a cylindrical external filter type filter, the water content of the scheelite concentrate has a mass ratio of 2% to 15%.

Referring to Figure 1, Figure 2, Figure 3, Figure 4 and Figure 5, the device for realizing the dehydration and drying method of scheelite concentrate, the outlet of the filter equipment is connected to the inlet of a microwave drying device 2, and the outlet of the microwave drying device 2 is connected to the air flow The inlet of the conveying device 15 and the outlet of the airflow conveying device 15 are connected with an automatic packing machine 16 .

Air-flow conveying device 15 also can replace with screw conveying device.

Filtration equipment includes: GW-type cylindrical external filter filter 1, GW-type cylindrical external filter filter is a ceramic filter or a box-type filter press, and the filtration vacuum pressure is stable above 0.8MPa.

The structure of the microwave drying device 2 includes: a material distribution device 3 (double toothed roll), a passive support 4, a dehumidification system 5, a suppression system 6, a box support 7, a cleaning window 8, a cooling pipeline 9, an electrical system 10, a microwave Cavity 11, active support 12 and discharge opening 13 and transport belt 14, transport belt 14 is polyurethane belt. The process parameters of the microwave drying device are: microwave frequency 2400-2500MHz, 8 groups in total, belt speed 0-1m/min (range adjustable), box temperature less than 45°C, microwave leakage less than 1mW/cm ² .

The structure of the air conveying device 15 includes: a feed inlet, a suction nozzle, a delivery pipe (lined with a ceramic pipe), a primary cyclone separator, a feed bin, a secondary cyclone separator, a blower fan and a discharge port.

Example 1:

⑴The water content of scheelite flotation concentrate is 40%, and the vacuum external filter cylinder filter is used for dehydration, and the water content of scheelite filtered concentrate is 3.85%.

⑵The tungsten filter concentrate is evenly distributed on the polyurethane conveyor belt, and the thickness of the scheelite concentrate is adjusted to 2.0cm, 6 groups of microwaves, and the belt speed is 0.588m/min. Finally, the scheelite concentrate has a water content of 0.07%.

Example 2:

⑴The water content of scheelite flotation concentrate is 50%, and the vacuum external filter cylinder filter is used for dehydration, and the water content of scheelite filtered concentrate is 15%.

⑵The tungsten filter concentrate is evenly distributed on the polyurethane conveyor belt, and the thickness of the scheelite concentrate is adjusted to 1.0cm, 8 groups of microwaves, and the belt speed is 0.488m/min. Finally, the water content of the scheelite concentrate is 1.98%.

Example 3:

⑴The moisture content of scheelite flotation concentrate is 30%, which is dehydrated by vacuum external filter cylinder filter, and the moisture content of scheelite filtered concentrate is 4.26%.

⑵The tungsten filter concentrate is evenly distributed on the polyurethane conveyor belt, and the thickness of the scheelite concentrate is adjusted to 3.0cm, 7 groups of microwaves, and the belt speed is 0.568m/min. Finally, the obtained scheelite concentrate has a water content of 0.26%.

Example 4:

⑴ The moisture content of scheelite flotation concentrate is 38%, and the vacuum external filter type cylindrical filter is used for dehydration, and the moisture content of scheelite filtered concentrate is 5.84%.

⑵The tungsten filter concentrate is evenly distributed on the polyurethane conveyor belt, and the thickness of the scheelite concentrate is adjusted to 2.6cm, 5 groups of microwaves, and the belt speed is 0.668m/min. Finally, the obtained scheelite concentrate has a water content of 0.30%.

Example 5:

⑴ The water content of the scheelite flotation concentrate is 43%, and the vacuum external filter cylinder filter is used for dehydration, and the water content of the scheelite filtered concentrate is 6.20%.

⑵The tungsten filter concentrate is evenly distributed on the polyurethane conveyor belt, and the thickness of the scheelite concentrate is adjusted to 1.8cm, 8 groups of microwaves, and the belt speed is 0.436m/min. Finally, the scheelite concentrate has a water content of 0.19%.

Claims (10)

1. A dehydration and drying method for scheelite concentrate is characterized in that: scheelite concentrate is filtered through a filtering device, and then passed through a cavity of a microwave drying device, and the static cloth moves on a belt and is dried by microwaves. 2. The dehydration and drying method of scheelite concentrate according to claim 1, characterized in that: said scheelite concentrate contains WO ₃ grade quality in 35% to 80.5%; the grain size of said scheelite concentrate The grade distribution-200 mesh mass ratio is 55%-96%; the water mass ratio of the scheelite concentrate is 30%-50%. 3. The method for dehydrating and drying scheelite concentrate according to claim 1 or 2, characterized in that it specifically comprises the following steps: firstly, the scheelite concentrate in the scheelite beneficiation plant is filtered by filtering equipment and then transported to the dry In the workshop, again, the static cloth moves slowly on the belt and is dried by a microwave device that generates microwaves. Finally, it is transported to the packing workshop through a set of conveying devices and packed by an automatic packing machine to obtain qualified products of scheelite concentrate. 4. The dehydration and drying method of scheelite concentrate according to claim 1 or 2, characterized in that: the static cloth thickness of the scheelite concentrate on the belt is 0.5cm-5cm. 5. The dehydration and drying process of scheelite concentrate according to claim 1 or 2, characterized in that: the microwave frequency is 2400-2500MHz, and the belt speed is 0m/min-1m/min. 6. The method of dehydration and drying of scheelite concentrate according to claim 1 or 2, characterized in that: after the flotation scheelite concentrate is filtered and dehydrated by a filter device, the mass ratio of water content in the scheelite concentrate is 2 %~15%. 7. The device for realizing the dehydration and drying method of scheelite concentrate according to claim 1, characterized in that: the outlet of the filtering equipment is connected to the inlet of a microwave drying device, and the outlet of the microwave drying device is connected to the inlet of the conveying device , the outlet of the conveying device is connected to an automatic packing machine. 8. The device for the dehydration and drying method of scheelite concentrate according to claim 7, characterized in that: the filter equipment is a cylindrical external filter filter, and the filter vacuum pressure is stable above 0.8MPa. 9. The device for the dehydration and drying method of scheelite concentrate according to claim 7 or 8, characterized in that: the structure of the microwave drying device includes: a material distribution device, a passive support, a dehumidification system, a suppression system, a box Body support, cleaning window, cooling pipeline, electrical system, microwave cavity, active support, feeding port and conveying belt. 10. The device for the dehydration and drying method of scheelite concentrate according to claim 7 or 8, characterized in that: the conveying device is an air conveying device or a screw conveying device, and the structure of the air conveying device includes: Feed inlet, suction nozzle, conveying pipe, primary cyclone separator, silo, secondary cyclone separator, fan and discharge port.