Platinum-palladium ore flotation concentrate smelting method based on flash smelting furnace

Abstract

The invention relates to a platinum-palladium ore flotation concentrate smelting method based on a flash smelting furnace, which comprises the following steps: firstly, drying platinum-palladium flotation concentrate, then mixing the dried and dehydrated dry concentrate with a flux, an auxiliary material and a return material, carrying out pneumatic conveying, conveying the mixture to the flash smelting furnace through a concentrate nozzle, and carrying out smelting in a reaction tower of the flash smelting furnace, so as to obtain the platinum-palladium ore flotation concentrate. And carrying out gas-solid reaction within the time of not more than 2 seconds to generate low-nickel copper matte rich in platinum group metals, enabling the low-nickel copper matte and the smelting slag to fall into a settling pond, then conveying the low-nickel copper matte to a converting furnace through a chute, and carrying out slagging and iron removal to generate high-nickel copper matte rich in platinum group metals. According to the method, the recovery rate and the heat utilization rate of the platinum group metal in the platinum-palladium flotation concentrate pyrometallurgy process can be effectively increased, the smelting time is greatly shortened, in addition, high-nickel-copper matte containing high-grade platinum and palladium serves as a final qualified pyrometallurgy product according to the sulfur affinity and the iron affinity of the platinum group metal element, the platinum group metal element can be early recovered, and the recovery rate of the platinum group metal element is greatly increased. And subsequent wet smelting is facilitated, and the comprehensive recovery rate of the platinum-palladium ore is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal smelting, and in particular relates to a flotation concentrate smelting method of platinum-palladium ore based on a flash smelting furnace. Background Art

[0002] At present, flotation is still the main method for processing platinum-palladium ore, and pyrometallurgy is usually the main method for processing platinum-palladium flotation concentrate. The conventional platinum-palladium metal extraction process firstly enriches the platinum-palladium ore by flotation, then further enriches it by pyrometallurgy, and then uses hydrometallurgical methods to separate the precious and base metals to extract the pure metal of the platinum group metals.

[0003] According to the different properties of flotation concentrate, the smelting processes vary, including the electric furnace-PS converter process, the electric furnace-Kaldo furnace process, the Ausmelt furnace-PS converter process, etc. These methods have achieved good smelting indicators when processing platinum-palladium flotation concentrate. However, the low reaction efficiency and high energy consumption of platinum-palladium flotation concentrate in the electric furnace smelting process and the existence of low-air pollution problems in the PS converter blowing process will reduce the recovery rate of platinum-palladium concentrate and deteriorate the operating environment, thereby affecting subsequent smelting indicators. Summary of the invention

[0004] The present invention provides a method for smelting a platinum-palladium ore flotation concentrate based on a flash smelting furnace, and aims to effectively improve the recovery rate and heat utilization rate of platinum group metals in the pyrometallurgical smelting process of the platinum-palladium flotation concentrate through continuous operation of the platinum-palladium flotation concentrate in the pyrometallurgical smelting process, that is, continuous smelting and blowing processes, and improve the operating environment to achieve early recovery of platinum group metal elements, which is beneficial to the subsequent hydrometallurgical smelting of platinum-palladium ore and improve the comprehensive recovery rate of the platinum-palladium ore.

[0005] In order to solve the above technical problems, the present invention provides a flotation concentrate smelting method of platinum-palladium ore based on a flash smelting furnace, characterized in that it comprises the following steps:

[0006] Step 1, drying the flotation concentrate to obtain a dry concentrate, so that the moisture content of the dry concentrate is 0% to 2%;

[0007] Step 2, batching the dry concentrate from step 1;

[0008] Step 3, the mixed concentrate after batching in step 2 is pneumatically conveyed through the concentrate nozzle to the flash smelting furnace. In the reaction tower at the upper part of the flash smelting furnace, the large specific surface area of ​​the powder material is conducive to the occurrence of chemical reactions, and a gas-solid reaction occurs within a time of no more than 2 seconds to generate low-nickel copper matte rich in platinum group metals and smelting slag, which fall into the sedimentation tank at the lower part of the flash furnace. After clarification and stratification, the low-nickel copper matte rich in platinum group metals in the lower layer is conveyed to the converting furnace through the chute;

[0009] Step 4: The low-nickel copper matte rich in platinum group metals produced in step 3 is smelted in a smelting furnace to produce a high-nickel copper matte rich in platinum group metals.

[0010] Beneficial effects: The platinum-palladium ore flotation concentrate product of the present invention is subjected to drying pretreatment and flash smelting to improve the smelting reaction rate of the platinum-palladium ore flotation concentrate. This method can greatly shorten the smelting reaction time of the platinum-palladium ore flotation concentrate, provide a larger operating space for subsequent blowing, and comprehensively improve the recovery rate of platinum group metals. The specific advantages are as follows:

[0011] (1) By pre-drying the flotation concentrate, the moisture content of the platinum-palladium ore flotation concentrate can be reduced to an extremely low level, thereby reducing the energy consumption of the flash smelting furnace and improving the smelting operation intensity;

[0012] (2) Flash smelting of the dried flotation concentrate, i.e., enhanced smelting, is carried out. Its unique gas-solid reaction effectively shortens the smelting reaction time, and can achieve early recovery of platinum group metal elements, which is beneficial to improving the smelting recovery rate of platinum group elements;

[0013] (3) The platinum-palladium ore flotation concentrate is subjected to continuous smelting and blowing, that is, the low-nickel-copper matte after smelting enters the blowing furnace through a chute, which saves the equipment investment and heat loss of the bun transportation, is conducive to energy conservation and emission reduction and improves the smelting recovery rate of platinum group elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below.

[0016] The present invention proposes a method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace, comprising the following steps:

[0017] Step 1, drying the flotation concentrate, the concentrate product particle size is -74μm particle content accounts for 60%, the concentrate moisture content is 0% to 2%, preferably 0.1% to 0.5%;

[0018] Step 2, adding a certain amount of flux (5% to 30%, including but not limited to one of limestone, lime, and quartz), auxiliary materials (0.5% to 8%, coal powder) and return materials (2% to 15%, smoke) to the dry concentrate product of step 1 for batching;

[0019] Step 3, the mixed concentrate after batching in step 2 is pneumatically conveyed through the concentrate nozzle to the flash smelting furnace. In the reaction tower at the upper part of the flash smelting furnace, the large specific surface area of ​​the powder material is conducive to the occurrence of chemical reactions, and a gas-solid reaction occurs within a time of no more than 2 seconds to generate low-nickel copper matte rich in platinum group metals and smelting slag, which fall into the sedimentation tank at the lower part of the flash furnace. After clarification and stratification, the low-nickel copper matte rich in platinum group metals in the lower layer is conveyed to the converting furnace through the chute, and the slag in the upper layer is sent to the depletion electric furnace;

[0020] The present invention adopts pneumatic conveying after batching, and adds the concentrate to the top of the flash furnace reaction tower through the concentrate nozzle. The pneumatic conveying method is dust-free and environmentally friendly.

[0021] The operating temperature of the flash smelting furnace is 1150-1500°C, and further may be 1200-1400°C.

[0022] Step 4, converting the low-nickel copper matte rich in platinum group metals in step 3 into a high-nickel copper matte rich in platinum group metals by a converting furnace;

[0023] The low-nickel copper matte produced by the flash smelting furnace is transported to the converting furnace via a chute, eliminating the equipment investment and heat loss of transporting the matte.

[0024] Step 5, depleting the slag from step 3 by a depletion electric furnace to produce low-nickel copper matte;

[0025] Step six, return to step four for the low nickel copper matte in step five.

[0026] The flue gas produced by flash smelting furnaces and converting furnaces has a high concentration of sulfur dioxide, which is easy to produce acid.

[0027] The smelting furnace used in the present invention is a flash furnace, and the smelting method is an enhanced smelting. In the reaction tower of the flash smelting furnace, the large specific surface area of ​​the powdered material is used to facilitate the chemical reaction, and a gas-solid reaction occurs within a time of no more than 2 seconds. Compared with traditional electric furnace smelting, flash smelting has the advantages of extremely fast reaction speed and high efficiency.

[0028] The core technology of this process is rapid intensified smelting and continuous smelting. The smelting furnace directly discharges low-nickel copper matte to the blowing furnace through the chute without falling over, and the reaction is rapid.

[0029] The present invention utilizes the characteristics of powdered materials that the large specific surface area is conducive to chemical reactions, and a gas-solid reaction occurs within a time of no more than 2 seconds to generate low-nickel copper matte rich in platinum group metals. The present invention can effectively improve the recovery rate and heat utilization rate of platinum group metals in the pyrometallurgical smelting process of platinum palladium flotation concentrate, greatly shorten the smelting time, and in addition, according to the sulfur affinity and iron affinity of platinum group metal elements, high-nickel-copper matte containing high-grade platinum palladium is used as the final qualified pyrometallurgical product, realizing the early recovery of platinum group metal elements, facilitating the subsequent hydrometallurgical smelting, and improving the comprehensive recovery rate of platinum palladium ore.

[0030] This will be described below with reference to specific embodiments.

[0031] Example 1

[0032] The platinum grade of a platinum-palladium flotation concentrate is 40.7 g / t, the palladium grade is 38.3 g / t, the nickel content is 4.2 wt%, the copper content is 3.6 wt%, the sulfur content is 18.4 wt%, and the magnesium oxide content is 22.1 wt%. 将 The concentrate (100 parts by weight), flux (10 parts by weight of lime), auxiliary material (1 powder by weight of coal powder), and return material (5 parts by weight of smelting + blowing dust) are mixed and pneumatically conveyed through the concentrate nozzle to the flash furnace reaction tower. The large specific surface area of ​​the powdered material is conducive to the occurrence of chemical reactions, and a gas-solid reaction occurs within a time of no more than 2 seconds, and the temperature of the molten pool is controlled at 1400°C. The low-nickel copper matte rich in platinum group metals generated in the flash furnace is discharged through the chute, and the excess slag is discharged to the depletion electric furnace for depletion. The low-nickel copper matte rich in platinum group metals is blown in a top-blown furnace to make slag and remove iron, and a flux (10 parts by weight of quartz) is added to produce a high-nickel copper matte rich in platinum group metals. After smelting and blowing, the yield of platinum group metals is 97.59%, and the smelting reaction takes 0.2-0.4h. The smelting time is significantly shorter than that of electric furnace smelting, and the recovery rate of platinum group metals is increased by 0.4-1.1 percentage points.

[0033] Example 2

[0034] The total grade of platinum and palladium in a platinum-palladium flotation concentrate is 151 g / t, the nickel content is 2.1 wt%, the copper content is 1.0 wt%, the sulfur content is 7.1 wt%, and the magnesium oxide content is 17.2 wt%. 将该精矿(质量1 00 parts), flux (lime weight 5 parts), auxiliary material (coal weight 1 powder), return material (melting + blowing dust weight 5 parts in total) are mixed and then pneumatically conveyed through the concentrate nozzle to the flash furnace reaction tower. The powder material has a large specific surface area that is conducive to chemical reactions, and a gas-solid reaction occurs within 2 seconds. 熔池温度控制在1360℃. The low-nickel copper matte rich in platinum group metals generated in the flash furnace is discharged through the chute, and the excess slag is discharged to the depletion electric furnace for depletion. The low-nickel copper matte rich in platinum group metals is blown in a top-blown blowing furnace to make slag and remove iron, and a flux (10 parts by mass of quartz) is added to produce high-nickel copper matte rich in platinum group metals. After smelting and blowing, the yield of platinum group metals is 98.23%, and the smelting reaction takes 0.2-0.35h. The smelting time is significantly shortened compared to the electric furnace smelting time, and the recovery rate of platinum group metals is increased by 0.8-1.3 percentage points.

[0035] The smelting method of the present invention used in the above embodiment can significantly reduce the smelting reaction time and improve the yield of platinum group metals. In addition, according to the characteristics of pyrometallurgy, high-nickel copper matte rich in platinum group metals is used as the final qualified product of pyrometallurgy, thereby achieving early recovery of platinum group elements and helping to improve the comprehensive recovery rate of platinum-palladium ore.

[0036] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace, characterized in that: The following steps are involved: Step 1, drying the flotation concentrate to obtain a dry concentrate, so that the moisture content of the dry concentrate is 0% to 2%; Step 2, batching the dry concentrate from step 1; Step 3, the mixed concentrate after batching in step 2 is pneumatically conveyed through the concentrate nozzle to the flash smelting furnace. In the reaction tower at the upper part of the flash smelting furnace, the large specific surface area of ​​the powder material is conducive to the occurrence of chemical reactions, and a gas-solid reaction occurs within a time of no more than 2 seconds to generate low-nickel copper matte rich in platinum group metals and smelting slag, which fall into the sedimentation tank at the lower part of the flash furnace. After clarification and stratification, the low-nickel copper matte rich in platinum group metals in the lower layer is conveyed to the converting furnace through the chute; Step 4: The low-nickel copper matte rich in platinum group metals produced in step 3 is smelted in a smelting furnace to produce a high-nickel copper matte rich in platinum group metals.

2. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 1, characterized in that: In step 1, the moisture content of the dry concentrate is 0.1% to 0.5%.

3. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 1, characterized in that: In step 2, a certain amount of flux, auxiliary materials and return materials are added to the dry concentrate of step 1 for batching.

4. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 3, characterized in that: The flux is one of limestone, lime and quartz, and its content is 5% to 30% of the mass of dry concentrate.

5. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 3, characterized in that: The auxiliary material is coal powder, and its content is 0.5% to 8% of the mass of dry concentrate.

6. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 3, characterized in that: The returned material is smoke dust, and its content is 2% to 15% of the mass of dry concentrate.

7. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 1, characterized in that: In step three, the upper layer of slag is sent to a depletion furnace for depletion to produce low-nickel copper matte, and then returns to step four.

8. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 1, characterized in that: The operating temperature of the flash smelting furnace is 1150-1500℃.

9. The method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to claim 1, characterized in that: The operating temperature of the flash smelting furnace is 1200-1400℃.

10. A method for smelting platinum-palladium ore flotation concentrate based on a flash smelting furnace according to any one of claims 1 to 9, characterized in that: The flue gas produced by flash smelting furnaces and converting furnaces has a high concentration of sulfur dioxide, which is easy to produce acid.

Images