阅读说明：本技术 一种细粒级高硅低铁锌精矿沸腾炉焙烧处理方法 (Fluidized bed furnace roasting treatment method for fine-grained high-silicon low-iron zinc concentrate ) 是由 宁时和 陈杭 衷水平 杨旭生 万学武 张恒星 赵玉文 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种细粒级高硅低铁锌精矿沸腾炉焙烧处理方法,(1)将细粒级高硅低铁锌精矿通过抛料机送入沸腾炉中；(2)通过控制炉前风机、助燃风机,来控制沸腾炉的焙烧参数,使锌精矿在流化床层进行850-920℃低温氧化焙烧,产物有焙砂、烟尘和烟气；(3)焙砂从沸腾炉的溢流口排出,经过冷却和球磨后进入焙砂仓,烟尘和烟气依次经过余热锅炉、旋涡收尘、电收尘进行余热回收和烟尘收集,产生的余热进汽包,收集的烟尘进入焙砂仓。本发明可有效减少焙砂中可溶硅的含量,并有效地降低烟尘率,减轻余热锅炉、旋涡收尘、电收尘等设备的负担,并降低工人的劳动强度。(The invention discloses a roasting treatment method of a fine-grained high-silicon low-iron zinc concentrate in a fluidized bed furnace, which comprises the following steps of (1) feeding the fine-grained high-silicon low-iron zinc concentrate into the fluidized bed furnace through a thrower; (2) controlling roasting parameters of the fluidized bed furnace by controlling a stokehole fan and a combustion-supporting fan, so that the zinc concentrate is subjected to 850-plus 920-DEG C low-temperature oxidizing roasting in the fluidized bed layer, and the product comprises calcine, smoke dust and flue gas; (3) discharging the calcine from an overflow port of the fluidized bed furnace, cooling and ball-milling the calcine, then feeding the calcine into a calcine bin, sequentially carrying out waste heat recovery and smoke dust collection on smoke dust and flue gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, and feeding the collected smoke dust into the calcine bin. The invention can effectively reduce the content of soluble silicon in the calcine, effectively reduce the smoke dust rate, lighten the burden of equipment such as a waste heat boiler, vortex dust collection, electric dust collection and the like, and reduce the labor intensity of workers.)

1. A fluidized bed roaster roasting treatment method for fine-grained high-silicon low-iron zinc concentrate is characterized by comprising the following specific steps:

(1) sending fine-grained high-silicon low-iron zinc concentrate into a fluidized bed furnace through a throwing machine;

(2) controlling roasting parameters of the fluidized bed furnace by controlling a stokehole fan and a combustion-supporting fan, so that the zinc concentrate is subjected to 850-plus 920-DEG C low-temperature oxidizing roasting on a fluidized bed layer of the fluidized bed furnace, and products comprise roasted sand, smoke dust and flue gas;

(3) discharging the calcine from an overflow port of the fluidized bed furnace, cooling and ball-milling the calcine, then feeding the calcine into a calcine bin, sequentially carrying out waste heat recovery and smoke dust collection on smoke dust and flue gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, and feeding the collected smoke dust into the calcine bin.

2. The method as claimed in claim 1, wherein in the fine-grained high-silicon low-iron zinc concentrate in the step (1), the mass ratio of particles with the grain diameter of less than or equal to 0.074mm is more than or equal to 60 percent, and the mass content of silicon dioxide is more than or equal to 3 percent and less than or equal to 8 percent.

3. The method of claim 1, wherein in step (1), the effective hearth area of the fluidized bed furnace is 109m²。

4. The method according to claim 1 or 2, wherein in the step (1), the upper straight section of the boiling furnace is increased by 1-3m based on the original height of 7.4 m.

5. The method of claim 1, wherein in the step (2), the roasting parameters of the fluidized bed roaster are as follows: air-material ratio of 1500-1800m³T, air excess coefficient 1.0-1.3.

Technical Field

The invention relates to the technical field of zinc smelting, in particular to a roasting treatment method of fine-grained high-silicon low-iron zinc concentrate in a fluidized bed roaster.

Background

The zinc smelting method for treating the zinc sulfide concentrate comprises a fire method and a wet method, and the zinc sulfide concentrate needs to be roasted in the first step whether the wet method or the fire method is adopted. The fluidized bed furnace has the characteristics of large heat capacity, uniform distribution of a thermal field, small temperature difference at each position in the furnace, high reaction speed, high roasting strength, simple operation, high heat and mass transfer efficiency between solid and gas and the like, and is widely applied to roasting zinc concentrate. Wherein, the temperature, the air flow characteristic and the physical and chemical properties of the zinc concentrate have great influence on calcine, smoke dust, smoke and the like of roasting reaction products.

At present, most zinc smelting plants raise the roasting temperature (950-. However, zinc concentrate produced in a certain mine has the characteristics of high silicon and low iron in terms of components, and soluble silicon in the roasted product can be increased by using the existing roasting operation conditions. The high silicon content in the zinc concentrate can lead to the generation of low-melting-point silicate during boiling roasting, so that the roasted sand agglomeration deteriorates the furnace condition. The silicate in the calcine is easy to leach under an acidic condition to generate silica sol or gel, so that the leached ore pulp is difficult to separate liquid from solid, the yield of supernatant is low, the supernatant is easy to run and mix, and the like. In addition, the produced high silicic acid leaching residue is directly volatilized by the rotary kiln, which causes the problems of low volatilization rate of zinc and lead, serious ring formation of the rotary kiln and the like. Therefore, silicon is very harmful to zinc hydrometallurgy, and the content of soluble silicon needs to be reduced as much as possible in the roasting process. Physically, the particles of the zinc concentrate are fine, and more than 60 percent of the particles are larger than 200 meshes. In the boiling roasting process, the fine zinc concentrate can increase the smoke dust rate, increase the burden of waste heat boilers, electric dust collection and other equipment, and increase the labor capacity of workers. Therefore, a fluidized bed furnace roasting treatment method for fine-grained high-silicon low-iron zinc concentrate is needed.

The Chinese patent application with publication number CN111961840A discloses a roasting treatment process of a high As and high S tin concentrate fluidized bed furnace, which utilizes oxygen-enriched roasting, controls weak oxidizing atmosphere in the fluidized bed furnace during roasting, removes part of arsenic during roasting desulfurization, reduces labor intensity of workers, reduces wood consumption, protects natural resources, improves working environment and reduces environmental pollution. Chinese patent application publication No. CN102660673A discloses a roasting process and apparatus for a fluidized bed furnace for strengthening high-sulfur pyrite concentrate, which reduces sulfur content in sulfuric acid slag and improves utilization rate of sulfur resources by designing fluidized bed furnace type, feeding device, strengthening airflow distribution in the fluidized bed furnace, and other measures. The chinese patent application No. CN203128198U discloses an improved fluidized bed furnace, which can improve the reaction efficiency of pyrite in the furnace body, so that pyrite can be fully combusted. These inventions propose improvements to the high arsenic and high sulfur tin concentrate treatment process and the structure of the fluidized bed furnace. However, none of the above methods solves the problems of the fine-grained high-silicon low-iron zinc concentrate in the fluidized bed roasting.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a fluidized bed roasting treatment method for fine-grained high-silicon low-iron zinc concentrate.

In order to achieve the purpose, the invention adopts the following technical scheme:

a fluidized bed furnace roasting treatment method for fine-grained high-silicon low-iron zinc concentrate comprises the following specific steps:

(1) sending fine-grained high-silicon low-iron zinc concentrate into a fluidized bed furnace through a throwing machine;

(2) controlling roasting parameters of the fluidized bed furnace by controlling a stokehole fan and a combustion-supporting fan, so that the zinc concentrate is subjected to 850-plus 920-DEG C low-temperature oxidizing roasting on a fluidized bed layer of the fluidized bed furnace, and products comprise roasted sand, smoke dust and flue gas;

(3) discharging the calcine from an overflow port of the fluidized bed furnace, cooling and ball-milling the calcine, then feeding the calcine into a calcine bin, sequentially carrying out waste heat recovery and smoke dust collection on smoke dust and flue gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, and feeding the collected smoke dust into the calcine bin.

Further, in the fine-grained high-silicon low-iron zinc concentrate in the step (1), the mass ratio of particles with the grain size of less than or equal to 0.074mm is more than or equal to 60 percent, and the mass content of silicon dioxide is more than or equal to 3 percent and less than or equal to 8 percent.

Further, in the step (1), the effective hearth area of the fluidized bed furnace is 109m²。

Further, in the step (1), the upper straight section of the boiling furnace is increased by 1-3m on the basis of the original height of 7.4 m.

Further, in the step (2), the roasting parameters of the fluidized bed roaster are as follows: air-material ratio of 1500-1800m³T, air excess coefficient 1.0-1.3.

The invention has the beneficial effects that:

(1) the invention improves the fluidized bed furnace, increases the height of the upper straight section of the fluidized bed furnace on the original basis, can effectively reduce the smoke dust rate in the fluidized bed roasting process, lightens the burden of devices such as a waste heat boiler, vortex dust collection, electric dust collection and the like, and reduces the labor intensity of workers.

(2) The invention can effectively reduce the content of soluble silicon in the calcine by controlling the roasting operation parameters and adopting low-temperature oxidizing roasting, and avoids the problems of the calcine agglomeration, the deterioration of furnace conditions, difficult liquid-solid separation of leached ore pulp, ring formation of a rotary kiln and the like.

(3) By the treatment method of the invention, finer concentrate materials can be effectively treated, and the treatment of concentrates with high silicon content has advantages.

Drawings

FIG. 1 is a schematic flow chart of examples 1 to 3 of the present invention;

FIG. 2 is a schematic view of a fluidized bed furnace according to examples 1 to 3 of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, and it should be noted that the present embodiment is based on the technical solution, and the detailed implementation and the specific operation process are provided, but the protection scope of the present invention is not limited to the present embodiment.

Example 1

A fluidized bed combustion roasting treatment method for fine-grained high-silicon low-iron zinc concentrate comprises the following specific processes as shown in figure 1:

sending fine-grained high-silicon low-iron zinc concentrate into an effective area of 109m by a throwing machine²The fluidized bed layer height in the fluidized bed furnace of (1). The excess air coefficient is controlled to be 1.3 and the air-material ratio is controlled to be 1800m by controlling a stokehold fan and a combustion-supporting fan³T, controlling the roasting temperature to 850 ℃, and carrying out low-temperature oxidation roasting on the zinc concentrate in the fluidized bed layer; discharging the product calcine from an overflow port of the fluidized bed furnace, cooling the product calcine by a cooling cylinder and ball milling the product calcine by a ball mill, then feeding the product smoke dust and smoke gas into a calcine bin after waste heat recovery and smoke dust collection of the product smoke dust and smoke gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the smoke dust generated by the waste heat boiler into the cooling cylinder, grinding the smoke dust by the ball mill, then feeding the smoke dust into the calcine bin, feeding the smoke dust collected by the vortex dust collection and the electric dust collection into a middle bin, and feeding the generated waste heat into a steam drum. The upper straight section of the fluidized bed furnace is transformed into a schematic diagram as shown in figure 2. In FIG. 2, H₁Denotes the fluidized bed layer, H₂Represents the height of the lower straight section, H₃Denotes the diffuser height, H₄Represents the original upper straight section height H₄+H_xIndicating the height of the upper straight section after modification, H_xIndicating that the retrofit increases height.

In this example, the particle size of the zinc concentrate is shown in table 1. The firing conditions and firing results are shown in Table 2.

Table 1 particle size of zinc concentrate

Particle size (mm)	>0.074	0.074-0.04	0.040-0.020	0.020-0.010	<0.010
						％	40	20	16	10	14

TABLE 2 calcination conditions and results

Example 2

The embodiment provides a roasting treatment method of fine-grained high-silicon low-iron zinc concentrate in a fluidized bed furnace, which comprises the following specific steps:

sending fine-grained high-silicon low-iron zinc concentrate into an effective area of 109m by a throwing machine²The fluidized bed layer height of the fluidized bed furnace of (1) was 1 m. The excess air coefficient is controlled to be 1.2 and the air-material ratio is controlled to be 1700m by controlling a stokehold fan and a combustion-supporting fan³T, controlling the roasting temperature at 900 ℃, and carrying out low-temperature oxidation roasting on the zinc concentrate in a fluidized bed layer; discharging the product calcine from the overflow port, cooling by the cooling cylinder and ball milling by the ball mill, then feeding the product calcine into the calcine bin, performing waste heat recovery and smoke dust collection on the product smoke dust and smoke gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, feeding the smoke dust collected by the vortex dust collection and the electric dust collection into the calcine bin through a middle bin, and feeding the residual smoke dust in the waste heat boiler into the calcine bin after ball milling. In this example, the particle size of the zinc concentrate is shown in table 3. The firing conditions and firing results are shown in Table 4.

TABLE 3 particle size of zinc concentrate

Particle size (mm)	>0.074	0.074-0.04	0.040-0.020	0.020-0.010	<0.010
						％	35	23	17	10	15

TABLE 4 calcination conditions and results

Example 3

The embodiment provides a roasting treatment method of fine-grained high-silicon low-iron zinc concentrate in a fluidized bed furnace, which comprises the following specific steps:

sending fine-grained high-silicon low-iron zinc concentrate into an effective area of 109m by a throwing machine²In the fluidized bed furnace, the fluidized bed height is 1 m. The excess air coefficient is controlled to be 1.1 and the air-material ratio is controlled to be 1600m by controlling a stokehold fan and a combustion-supporting fan³T, controlling the roasting temperature at 920 ℃, and leading the zinc concentrate to be low in the fluidized bed layerCarrying out warm oxidation roasting; discharging the product calcine from an overflow port of the fluidized bed furnace, cooling the product calcine by a cooling cylinder and ball milling by a ball mill, then feeding the product calcine into a calcine bin, performing waste heat recovery and smoke dust collection on the product smoke dust and smoke gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, feeding the smoke dust collected by the vortex dust collection and the electric dust collection into the calcine bin by a middle bin, and feeding the residual smoke dust in the waste heat boiler into the calcine bin after ball milling. In this example, the particle size of the zinc concentrate is shown in table 5. The firing conditions and firing results are shown in Table 6.

TABLE 5 particle size of zinc concentrate

Particle size (mm)	>0.074	0.074-0.04	0.040-0.020	0.020-0.010	<0.010
						％	30	26	18	11	15

TABLE 6 calcination conditions and results

Example 4

The embodiment provides a roasting treatment method of fine-grained high-silicon low-iron zinc concentrate in a fluidized bed furnace, which comprises the following specific steps:

sending fine-grained high-silicon low-iron zinc concentrate into an effective area of 109m by a throwing machine²The fluidized bed layer height of the fluidized bed furnace of (1) was 1 m. The excess air coefficient is controlled to be 1.0 and the air-material ratio is 1500m by controlling a stokehold fan and a combustion-supporting fan³And t, controlling the roasting temperature to be 900 ℃, and carrying out low-temperature oxidation roasting on the zinc concentrate in the fluidized bed layer. Discharging the product calcine from the overflow port, cooling by the cooling cylinder and ball milling by the ball mill, then feeding the product calcine into the calcine bin, performing waste heat recovery and smoke dust collection on the product smoke dust and smoke gas by a waste heat boiler, vortex dust collection and electric dust collection, feeding the generated waste heat into a steam drum, feeding the smoke dust collected by the vortex dust collection and the electric dust collection into the calcine bin through a middle bin, and feeding the residual smoke dust in the waste heat boiler into the calcine bin after ball milling. In this example, the particle size of the zinc concentrate is shown in table 7. The firing conditions and firing results are shown in Table 8.

TABLE 7 particle size of zinc concentrate

Particle size (mm)	>0.074	0.074-0.04	0.040-0.020	0.020-0.010	<0.010
						％	35	23	17	10	15

TABLE 8 calcination conditions and results

As can be seen from tables 2, 4, 6 and 8, the fine-grained high-silicon low-iron zinc concentrate is roasted by the methods of examples 1 to 4 in the fluidized bed furnace, the soluble silicon content of the roasted product is low, and the smoke dust rate is effectively reduced by increasing the height of the upper straight section of the fluidized bed furnace.

Various corresponding changes and modifications can be made by those skilled in the art based on the above technical solutions and concepts, and all such changes and modifications should be included in the protection scope of the present invention.