Metallurgy comprehensive utilization method for industrial boiler ash

Abstract

The invention discloses a metallurgical comprehensive utilization method for industrial boiler soot. The method comprises the following steps: 1, mixing the industrial boiler soot with wet smelting slag for later use; 2, mixing the lead concentrate, the lead smoke dust, the industrial boiler soot and the wet-process smelting slag mixture with raw coal, granulating, and continuously adding into a metallurgical furnace for smelting; and 3, discharging lead-rich slag from a slag opening when the smelting meets the discharge condition, and feeding the flue gas to be used for preparing acid after waste heat recovery and dust collection. According to the method, components such as calcium and silicon in the industrial soot are mainly mixed with the wet-process smelting slag according to a certain proportion and then are subjected to pyrometallurgical treatment, so that the wet-process smelting slag can be treated in a pyrogenic system without arranging drying equipment, and the purposes of reducing the slag drying cost and improving the slag drying efficiency are achieved. And the consumption of auxiliary materials such as limestone and quartz sand in a pyrometallurgy system can be reduced by participating in metallurgical treatment, and the purpose of reducing the production cost is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of pyrometallurgy, and in particular relates to a metallurgical comprehensive utilization method of industrial boiler ash. Background Art

[0002] Invention patent (CN106834690A) A method for treating valuable metals in oxygen pressure leaching slag through Ausmelt furnace uses oxygen pressure leaching slag as a raw material, and puts it into Ausmelt furnace for pyrometallurgical smelting with lead fume and lead concentrate in proportion, producing crude lead while recovering valuable elements in oxygen pressure leaching slag. However, this method has the following problems:

[0003] 1) The oxygen pressure leaching slag has not been treated by drying equipment, so it has high moisture content, resulting in problems such as difficulty in feeding and poor furnace entry.

[0004] 2) If the oxygen pressure leaching residue is dried separately, not only will the process be complicated, but the processing cost will also be high.

[0005] 3) During the pyrometallurgical process, a certain proportion of limestone, quartz sand and other auxiliary materials need to be added to adjust the slag type.

[0006] Industrial boiler ash is a slag material produced during the heating process of enterprises in the north. The main treatment method is to sell it to other companies. On the one hand, there are few sales channels and it is difficult to sell it. On the other hand, most of the sales are at a loss. There is no relevant method for comprehensive metallurgical treatment of industrial boiler ash at home and abroad. Summary of the invention

[0007] In view of the above problems, the present invention mainly utilizes calcium, silicon and other components in industrial fly ash to mix with wet smelting slag in a certain proportion and then conducts pyrometallurgical treatment. It can realize that the wet smelting slag is sent to the pyrometallurgical system for treatment without setting up drying equipment, thereby reducing the slag drying cost. Participating in metallurgical treatment can realize the pyrometallurgical system to reduce the consumption of auxiliary materials such as limestone and quartz sand, thereby achieving the purpose of reducing production costs.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A method for comprehensive metallurgical utilization of industrial boiler ash, comprising the following steps:

[0010] The first step: mixing industrial boiler ash with hydrometallurgical slag for later use;

[0011] Step 2: The lead concentrate, lead smoke, industrial boiler ash and hydrometallurgical slag mixture are mixed with raw coal and granulated, and then continuously added into the metallurgical furnace for smelting;

[0012] Step 3: When the smelting reaches the discharge conditions, the lead-rich slag is discharged from the slag outlet, and the flue gas is sent to the acid plant after waste heat recovery and dust collection.

[0013] Preferably, the industrial boiler ash contains 20-30wt% calcium oxide and 20-50wt% silicon; the hydrometallurgical slag is hydrometallurgical zinc slag, sulfur tailings produced by oxygen pressure leaching sulfur flotation operation, acid leaching residue produced by conventional leaching process, iron slag produced by neutralization and iron removal process, and lead slag produced by zinc oxide smoke leaching;

[0014] The moisture content of the mixture of industrial boiler soot and hydrometallurgical slag is 6-12.5wt%, and the mass ratio of CaO to SiO2 is 0.35-0.6. The calcium-silicon ratio affects the metallurgical slag type. If it exceeds the calcium-silicon ratio, the melting point of the slag is high, and if it is less than the calcium-silicon ratio, the viscosity of the slag increases.

[0015] Preferably, the hydrometallurgical zinc slag contains 3-10wt% zinc, 8-20wt% sulfur and 100-400g / t Ag.

[0016] Preferably, in the second step, 10-30 t / h of lead material, 3-8 t / h of smoke, 5-30 t / h of a mixture of industrial boiler fly ash and hydrometallurgical slag, and 0.5-2 t / h of raw coal are mixed and granulated.

[0017] Preferably, the metallurgical furnace is a top-blown furnace or a side-blown furnace.

[0018] Preferably, the air volume controlled for smelting in the second step is: 2.5-4.5Nm 3 / s, oxygen content: 0.5-1.5Nm 3 / s, oxygen enrichment concentration: 25-35 v %, pulverized coal is sprayed into the molten pool as fuel through a spray gun, the pulverized coal feed rate to the spray gun is 1.2-2.5t / h, and the molten pool temperature is controlled at 850-1300℃; smelt at 850-1300℃ for 1-3 hours, adjust the pulverized coal feed rate to the spray gun to 1.5-2.5t / h, increase the oxygen dosage, and raise the temperature to 1100-1250℃.

[0019] Preferably, the material is added to the smelting process continuously, and lead-rich slag is released every 3-4 hours. The lead-rich slag is reduced and smelted in a second metallurgical furnace to release crude lead.

[0020] Preferably, in the third step of smelting, when the amount of material fed into the furnace reaches the rated amount and the slag contains 35-42wt% lead, lead-rich slag is discharged from the slag outlet.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention mixes industrial boiler ash with wet smelting slag and then smelts lead. The dried industrial boiler ash can balance the humidity of the wet smelting slag. The wet smelting slag does not need to be dried separately, and does not need to add auxiliary materials such as limestone. It can reduce auxiliary material consumption, reduce slag rate, increase metal input, and improve metal direct recovery rate and recovery rate. It also solves the problem of handling a large amount of industrial boiler ash. At the same time, adding industrial boiler ash has no effect on the purity of the lead after smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart of a method for comprehensive metallurgical utilization of industrial boiler ash. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention.

[0025] Example 1

[0026] A method for comprehensive metallurgical utilization of industrial boiler soot, comprising the following specific steps:

[0027] Table 1 Composition of each material (w%)

[0028]

[0029] 1) Mix the industrial boiler ash and the wet smelting slag in a ratio of 3.5:1, with the moisture content of the mixture being 6.67%, and place the mixture in a flux bin for standby use;

[0030] 2) Set the DCS to feed 10 t / h of lead material, 10 t / h of a mixture of industrial boiler soot and wet smelting slag, 3 t / h of soot, and 0.5 t / h of raw coal. After mixing and granulating, add them continuously into the metallurgical furnace (top-blown furnace) for smelting.

[0031] 3) Strictly control the spray gun process air volume during smelting: 2.5Nm 3 / s, oxygen quantity: 0.5Nm 3 / s, oxygen enrichment concentration is: 35%, and the pulverized coal feed rate to the spray gun is 1.2t / h.

[0032] 4) Control the furnace atmosphere and molten pool temperature to 1050°C;

[0033] 5) Smelting at 1050°C for 3 hours, the lead material reacts completely with the mixture of industrial boiler soot and wet smelting slag by adjusting the amount of pulverized coal or lump coal by 1 t / h, increasing the amount of oxygen, and raising the temperature to 1150°C;

[0034] 6) When the smelting reaches the discharge conditions, the lead-rich slag is discharged from the slag outlet, and the flue gas is sent to the acid plant after waste heat recovery and dust collection.

[0035] 7) Circular smelting, releasing lead-rich slag and crude lead every 3 hours.

[0036] Example 2

[0037] A method for comprehensive metallurgical utilization of industrial boiler soot, comprising the following specific steps:

[0038] Table 1 Composition of each material (w%)

[0039]

[0040] 1) Mix the industrial boiler ash and the wet smelting slag in a ratio of 2.5:1, with the moisture content of the mixture being 8.57%, and place them in a flux bin for standby use;

[0041] 2) Set the lead material to 15t / h, the mixed material to 15t / h, the smoke to 3t / h, and the raw coal to 0.75t / h on the DCS. After mixing and granulation, they are continuously added into the metallurgical furnace (side-blown furnace) for smelting.

[0042] 3) Strictly control the spray gun process air volume during smelting: 4.5Nm 3 / s, oxygen volume: 1Nm 3 / s, oxygen enrichment concentration is: 35%, and the pulverized coal feed rate to the spray gun is 1.2t / h.

[0043] 4) Control the furnace atmosphere and molten pool temperature to 1050°C;

[0044] 5) Smelting at 1050°C for 3 hours, the lead material reacts completely with the mixture of industrial boiler soot and hydrometallurgical slag by adjusting the amount of pulverized coal or lump coal by 1.5 t / h, increasing the amount of oxygen, and raising the temperature to 1150°C;

[0045] 6) When the smelting reaches the discharge conditions, the lead-rich slag is discharged from the slag outlet, and the flue gas is sent to the acid plant after waste heat recovery and dust collection.

[0046] 7) Circular smelting, releasing lead-rich slag and crude lead every 3 hours.

[0047] Example 3

[0048] A method for comprehensive metallurgical utilization of industrial boiler soot, comprising the following specific steps:

[0049] Table 1 Composition of each material (w%)

[0050]

[0051] 1) Mix the industrial boiler ash and the wet smelting slag in a ratio of 1.5:1, with the moisture content of the mixture being 12%, and place the mixture in a flux bin for standby use;

[0052] 2) Set the lead material at 15t / h, the mixed material at 20t / h, the smoke at 3t / h, and the raw coal at 1t / h on the DCS. After mixing and granulation, they are continuously added into the metallurgical furnace (bottom-blown furnace) for smelting.

[0053] 3) Strictly control the spray gun process air volume during smelting: 4.5Nm 3 / s, oxygen volume: 1Nm 3 / s, oxygen enrichment concentration is: 35%, and the pulverized coal feed rate to the spray gun is 1.2t / h.

[0054] 4) Control the furnace atmosphere and molten pool temperature to 1050°C;

[0055] 5) Smelting at 1050°C for 3 hours, the lead material reacts completely with the mixture of industrial boiler soot and hydrometallurgical slag by adjusting the amount of pulverized coal or lump coal by 1.5 t / h, increasing the amount of oxygen, and raising the temperature to 1150°C;

[0056] 6) When the smelting reaches the discharge conditions, the lead-rich slag is discharged from the slag outlet, and the flue gas is sent to the acid plant after waste heat recovery and dust collection.

[0057] 7) Circular smelting, releasing lead-rich slag and crude lead every 3 hours.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for comprehensive metallurgical utilization of industrial boiler ash, characterized in that: The following steps are involved: The first step: mixing industrial boiler ash with hydrometallurgical slag for later use; Step 2: The lead concentrate, lead smoke, industrial boiler ash and hydrometallurgical slag mixture are mixed with raw coal and granulated, and then continuously added into the metallurgical furnace for smelting; Step 3: When the smelting reaches the discharge conditions, the lead-rich slag is discharged from the slag outlet, and the flue gas is sent to the acid plant after waste heat recovery and dust collection.

2. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: The industrial boiler ash contains 20-30wt% calcium oxide and 20-50wt% silicon; the hydrometallurgical slag is hydrometallurgical zinc slag, sulfur tailings produced by oxygen pressure leaching sulfur flotation operation, acid leaching residue produced by conventional leaching process, iron slag produced by neutralization and iron removal process, and lead slag produced by zinc oxide smoke leaching; The water content of the mixture of industrial boiler soot and hydrometallurgical slag is 6-12.5wt%, and the mass ratio of CaO to SiO2 is 0.35-0.

6.

3. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 2, characterized in that: The hydrometallurgical zinc slag contains 3-10wt% zinc, 8-20wt% sulfur and 100-400g / t Ag.

4. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: In the second step, 10-30 t / h of lead material, 3-8 t / h of smoke, 5-30 t / h of a mixture of industrial boiler ash and hydrometallurgical slag, and 0.5-2 t / h of raw coal are mixed and granulated.

5. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: The metallurgical furnace is a top-blown furnace or a side-blown furnace.

6. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: In the second step, the controlled air volume for smelting is: 2.5-4.5Nm 3 / s, oxygen content: 0.5-1.5Nm 3 / s, oxygen enrichment concentration: 25-35 v %, pulverized coal is sprayed into the molten pool as fuel through a spray gun, the pulverized coal feed rate to the spray gun is 1.2-2.5t / h, and the molten pool temperature is controlled at 850-1200℃; smelt at 850-1200℃ for 1-3 hours, adjust the pulverized coal feed rate to the spray gun to 1.5-2.5t / h, increase the oxygen dosage, and raise the temperature to 1100-1250℃.

7. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: The material is added continuously during smelting, and lead-rich slag is released every 3-4 hours. The lead-rich slag is reduced and smelted in the second metallurgical furnace to release crude lead.

8. The method for comprehensive metallurgical utilization of industrial boiler ash according to claim 1, characterized in that: In the third step of smelting, when the amount of material fed into the furnace reaches the rated amount and the slag contains 35-42wt% lead, lead-rich slag is discharged from the slag outlet.

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