Copper smelting is a high energy consumption and high pollution industrial process, from ore crushing, roasting, smelting to refining, each process generates a large amount of dust. These dust particles not only contain metal particles such as copper, lead, and zinc, but also contain toxic gases such as sulfur dioxide and fluoride. They have the characteristics of strong corrosiveness, fine particle size, and high toxicity. Choosing suitable dust removal equipment is a core requirement for copper smelting enterprises to achieve environmental standards, ensure worker health and equipment safety.

Characteristics and difficulties in controlling copper smelting dust

The complexity of copper smelting dust poses multiple challenges to dust removal work. Firstly, the composition is complex and toxic, with dust containing heavy metals such as copper, arsenic, and cadmium. Long term exposure can lead to poisoning, and gases such as sulfur dioxide combine with water vapor to form acidic substances, exacerbating equipment corrosion; Secondly, the temperature is high, and the flue gas temperature in the smelting and refining process can reach 300-800 ℃, which is difficult for ordinary equipment materials to withstand; Thirdly, the particle size is small and the viscosity is strong, with most dust particles smaller than 10 microns, making it easy to adhere to the surface of the filter material and prone to coking at high temperatures, increasing the difficulty of dust cleaning; Fourthly, the dust concentration fluctuates greatly, from low concentration dust in the crushing process to high concentration flue gas in the roasting process, requiring equipment to have a wide range of processing capabilities.

Types and technological advantages of suitable dust removal equipment

1. High temperature and corrosion-resistant bag filter
Bag filter is the mainstream choice for copper smelting dust removal, but it requires special design for high temperature and corrosion characteristics. The core advantage lies in the use of high temperature resistant and acid alkali resistant materials for the filter bags. For example, P84 (polyimide) filter bags can withstand high temperatures of 260 ℃, while PTFE (polytetrafluoroethylene) filter bags can be used for a long time at 250 ℃ with excellent corrosion resistance; The shell is made of 316L stainless steel or carbon steel lined with glass flakes to resist acid gas erosion; The ash cleaning system adopts a high-temperature resistant pulse valve to ensure stable operation in high-temperature environments. In the copper refining workshop, this equipment can control the dust emission concentration below 5mg/m ³, while capturing more than 90% of valuable metal dust, achieving resource recovery.

2. Electric bag composite dust collector: efficient treatment of high concentration flue gas
For high concentration flue gas such as roasting and smelting (dust concentration can reach 1000-5000mg/m ³), an electric bag composite dust collector is an ideal solution. It combines the advantages of electrostatic precipitator and bag filter: the front stage electric field first removes 70% -80% of large particle dust and some acidic gases, reducing the load on the rear stage bag; The secondary filter bag deeply filters fine dust, with a total filtration efficiency of 99.99%. At the same time, the equipment is equipped with a pre cooling system to reduce the high-temperature flue gas to the tolerance range of the filter bag (such as below 200 ℃), and neutralize the acidic gas by spraying alkaline desulfurizer (such as lime powder) to reduce corrosion to the equipment. In large copper smelters, the single processing air volume of the electric bag composite dust collector can reach 100000 m ³/h, meeting the demand for high production capacity.

3. Combination of cyclone dust collector and wet dust collector: for special working conditions
The combination of cyclone dust collector and wet dust collector is more advantageous when dealing with high humidity and high viscosity copper smelting dust (such as the filter cake drying process in wet smelting). The cyclone dust collector first separates large particle dust and some water vapor to reduce the risk of blockage in subsequent equipment; Wet dust collectors absorb dust and acidic gases through alkaline spray solution (such as sodium hydroxide solution), achieving integrated treatment of "dust removal+desulfurization". The equipment is made of fiberglass or titanium alloy, which is resistant to acid and alkali corrosion, and the spray liquid can be recycled to reduce wastewater discharge. This combination is suitable for wet processes in small and medium-sized smelters, with low investment costs and easy maintenance.

Selection and Technical Points of Copper Smelting Dust Removal Equipment

1. Material and temperature resistance matching
Select equipment materials based on the temperature of different processes: for high-temperature sections (such as smelting flue gas), high-temperature resistant stainless steel (such as 310S) or ceramic lining is preferred; In the medium temperature range (such as roasting flue gas), 304 stainless steel and high temperature resistant coating can be used; Ordinary carbon steel with anti-corrosion treatment is selected for the low-temperature section (such as crushing process). The filter bag should be selected according to the temperature range to avoid high temperature burning or low temperature condensation.

2. Anti corrosion and safety design
The equipment needs to undergo comprehensive anti-corrosion treatment, such as acid pickling and passivation at the welding points of the shell, and flange sealing and anti-corrosion rubber pads for the pipeline; Install explosion-proof devices (such as explosion-proof valves) and toxic gas monitoring devices, which will automatically alarm and activate the emergency response system when the sulfur dioxide concentration exceeds the standard; Equipped with a high temperature warning device, the flue gas temperature is controlled within a safe range by mixing cold air or starting the cooler.

3. Resource recycling and environmental compliance
Dust removal equipment should integrate a dust recovery system to collect dust rich in copper, gold, and silver, which can reduce raw material loss and hazardous waste treatment costs. At the same time, it is necessary to meet international environmental standards, such as the limit requirements for heavy metal emissions in the EU's Industrial Emissions Directive (IED), and the control standards for harmful air pollutants (HAPs) by the US EPA.

4. Intelligent operation and maintenance
By installing temperature, pressure, and dust concentration sensors, real-time monitoring of equipment operation status is achieved, and combined with PLC control system, parameters such as dust cleaning frequency and cooling air volume are automatically adjusted; Establish a remote diagnostic platform to promptly detect issues such as damaged filter bags and blocked pipelines, reducing downtime.
The selection of copper smelting dust removal equipment should take into account multiple characteristics such as high temperature, corrosion, and toxicity. Through material optimization, structural design, and intelligent operation and maintenance, a balance between efficient purification and safe production can be achieved. For overseas copper smelting enterprises, suitable dust removal equipment is not only a prerequisite for environmental compliance, but also a key factor in improving resource utilization and reducing operating costs, helping enterprises establish a benchmark image for green smelting in the international market.