Given the complex composition of PCBs, their high organic content, and the significant variations in reaction conditions during processing, Metalcess offers an electronic waste recycling solution centered on TSL (Top Submerged Lance) molten bath smelting technology. This technology enhances molten bath smelting to achieve efficient enrichment and recovery of copper and precious metals from PCBs.

The TSL furnace inserts the refining lance directly into the slag layer of the melt bath. By utilizing high-velocity gas to create intense agitation within the melt bath and promote enhanced three-phase (gas-liquid-solid) reactions, it achieves efficient concentration of valuable metals from PCBs into the metal phase or copper-slag phase. At the same time, the chemical energy carried by resins and other organic components in the PCBs can directly contribute to the thermal balance within the furnace, providing a reliable technical foundation for large-scale, continuous electronic waste smelting.

TSL Molten Smelting—Direct Oxygen Injection into the Slag Layer

Unlike traditional methods that supply oxygen from the surface of the molten bath, the TSL furnace’s top-immersed lance is inserted directly into the molten bath. Oxidizing agents and refining gases are injected into the molten bath at high speed through the lance, creating a vigorous gas-liquid reaction zone around it.

For pretreated PCB feedstock, the organic components rapidly crack and carbonize under high-temperature conditions and participate in subsequent oxidation reactions.

Since the spray lance acts directly on the slag layer, it offers superior oxygen transfer capabilities:

Ø  Oxygen is delivered directly to the reaction zone containing carbonized PCB components;

Ø  It avoids the excessive mass transfer distance caused by traditional surface oxygen supply;

Ø  It accelerates the reaction between oxygen and carbonaceous materials;

Ø  Improves the combustion efficiency of the PCB’s organic components;

Ø  Enhances metallurgical reactions between metal oxides, sulfides, and the slag phase.

This characteristic of “direct gas injection into the melt bath—enhanced agitation—rapid mass transfer and reaction” makes TSL particularly suitable for processing secondary metal resources with fast reaction rates, complex compositions, and significant variations in calorific value.

The intense melt bath circulation in the TSL continuously transfers heat to the lower metal layers, maintaining good fluidity of the molten copper and creating favorable conditions for subsequent metal settling and separation.

The PCB’s Own Energy Contributes to Thermal Balance

PCBs typically contain a certain proportion of resins, plastics, and other organic components. Under high-temperature conditions, these organic materials decompose and release combustible gases and fixed carbon. By properly controlling the oxygen supply, a portion of the chemical energy inherent in the PCB is released within the melt bath and directly contributes to the smelting process. As the unreacted organic fumes rise, they mix with the secondary oxygen ejected from the middle of the torch and burn; the heat is transferred to the furnace via radiation, maintaining thermal equilibrium within the furnace.

Through proper material ratios and oxidizer control, the TSL smelting system can operate with lower external energy consumption.

Scalability of Processing Capacity

TSL furnaces typically feature a fixed furnace structure, with the core reaction carried out by top-immersion spray nozzles and pneumatic agitation within the melt bath.

Therefore, as processing volume increases, higher single-furnace processing capacity can be achieved by expanding: furnace diameter; bath volume; number of spray nozzles; gas supply capacity of the spray nozzles; and feeding volume.

Compared to equipment that requires rotation and tilting, TSL offers superior engineering adaptability for scaling up.

For those seeking to build:

•    Large-scale PCB recycling plants;

•    Continuous electronic waste treatment systems;

•    High-throughput copper and precious metal recovery projects;

TSL can serve as a highly competitive core smelting solution.

Comprehensive Flue Gas Treatment System

Although the TSL system generates a relatively large volume of flue gas, Metalcess can employ a comprehensive flue gas treatment process similar to that of the TBRC to perform multi-stage treatment of organic pollutants, acid gases, dust, and trace contaminants generated by PCB smelting.

A typical process flow includes: TSL furnace → secondary combustion chamber → quench system → dry desulfurization → baghouse filter → wet scrubbing → activated carbon adsorption → induced draft fan → compliant emissions

TSL PCB Recycling Solution Advantages

For PCB recycling projects requiring high processing capacity and continuous operation, the TSL’s enhanced molten bath smelting technology offers significant advantages.

Ø  Top-immersion spray nozzles act directly on the slag layer, providing strong oxygen transfer;

Ø  Intense molten bath agitation continuously renews the gas-liquid-solid three-phase reaction interface;

Ø  High heat transfer efficiency effectively transfers reaction heat to the molten copper below;

Ø  The chemical energy from the PCBs’ own organic compounds contributes to the furnace’s thermal balance;

Ø  The furnace body does not require large-scale rotation or tilting movements, making it easier to scale up the equipment;

Ø  It is suitable for establishing large-scale, continuous PCB and electronic waste treatment production lines;

Ø  It can be configured with comprehensive systems including a secondary combustion chamber, chiller, dry deacidification, baghouse dust collection, wet scrubbing, and activated carbon deep purification;

Ø  The comprehensive recovery rate of copper and precious metals can be further improved through subsequent electric furnace slag depletion;

Ø  It can form a complete industrial chain when integrated with black copper refining, anode casting, copper electrolysis, and precious metal refining systems.

For projects seeking high processing capacity, continuous production, and large-scale PCB recycling, TSL offers a competitive technical solution; whereas for projects that prioritize high oxygen concentration operations, low flue gas volume, and flexible batch processing capabilities, TBRC offers unique advantages.

Metalcess can select TBRC, TSL, or a combined metallurgical process for clients based on feed composition, processing scale, energy conditions, environmental requirements, and end-product specifications, achieving the optimal balance between technological advancement, metal recovery rates, environmental performance, and project economic benefits.