Jinlijia, a leader in scrap recycling, is one of China's best-managed companies and operates on a large scale. It collects mixed-metal scrap of various types, including demolition scrap and ELV (end-of-life vehicle) scrap, and processes and recycles 200,000t (tonnes) of this mixed scrap per year.
The first step in metal recycling is shredding. Jinlijia is able to shred an average 700t of mixed material each working day (approximately 10 hours), or 13,000t per month. In order to produce the required capacity, Jinlijia installed two shredders, one rated at 1,000hp (horsepower) and the other at 2,000hp, at its own facility. In addition, Jinlijia has a scrap shear and a scrap baler on-site, for additional scrap-steel production.
Breaking the bottleneck of the basic sorting line
Before the recent installation of the TOMRA FINDER, Jinlijia operated a relatively "basic" sorting line for simple and rough sorting. With this basic line, the scrap stream was sent to a drum-screen, after the ferrous metals had been removed, in order to separate fines less than 10mm (<10mm) in size. Scrap fines larger than 10mm then continued on to eddy-current sorting, resulting in the separation of mixed non-ferrous metals, collectively known as Zorba. Finally, large and bulky items of stainless steel were separated manually, by four workers. The performance of this basic line was very limited, and it was unable to fully recover the non-ferrous metals. Furthermore, only a very limited amount of stainless steel could be separated manually, and the full potential of Jinlijia's recycling operation could not be realised.
Diagram 1.0: Jinlijia's original sorting set-up before installation of the TOMRA FINDER
Jinlijia finds the FINDER
In order to break the bottleneck of this basic sorting line and recover more value from the recycling of stainless steel, Jinlijia started to look for solutions from a number of different sources. By chance, at a metals-industry conference in 2014, Jinlijia learned of the automated sorting and recycling systems available from TOMRA.
After talking with TOMRA experts, Jinlijia realised that a good deal of rich content, such as copper, aluminium, zinc and other non-ferrous metals, plus a lot of stainless steel and electric cabling, remained in the scrap stream, following eddy-current sorting. If these materials could be recycled, that could, potentially, lead to a great improvement in operational efficiency. TOMRA's FINDER could, possibly, provide the breakthrough required in the sorting line.
Following TOMRA's suggestion, Jinlijia sent samples of its discarded scrap, following processing on the basic line, to the TOMRA Test Center in Xiamen, where initial tests were performed. The results indicated that the recovery rate for non-ferrous metals could be enhanced to 99.1%, with their purity increased to 89%, while the recovery rate for stainless steel could be improved to 98%.
Together the TOMRA team and Jinlijia engaged in in-depth talks about how to improve the sorting line. TOMRA’s Senior Account Manager then designed a line specifically for sorting the non-ferrous metals. The design was based on multiple years of industry experience and successful use cases, in a number of different countries. The re-designed sorting process is indicated below (diagram 2.0).
Diagram 2.0: New non-ferrous line with TOMRA FINDER
In the redesigned non-ferrous metal sorting flow, the shredded scrap is first subjected to strong magnetic sorting, in order to remove the magnetic ferrous metals. The resulting stream, containing no magnetic ferrous metal, is then separated, by drum-screen filtering, into four categories by size: <15mm; 15-30mm; 30-60mm, and >60mm. Then, scrap in each of the four size categories proceeds to eddy-current sorting. The resulting output is a mixture of non-ferrous metals, Zorba, containing copper, aluminium, zinc and other metals. The remaining scrap consists mainly of stainless steel and electric cabling, plus non-ferrous metals that the eddy-current stage failed to separate. What then remains unsorted proceeds to the TOMRA FINDER, which then sorts all the remaining metals, including the stainless steel.
The TOMRA local team continuously played a consultative role in the technical design of the new line and selection of equipment. In addition, the TOMRA local team also provided professional and timely technical support in the installation of the FINDER system and its routine maintenance. Commenting on the excellence of TOMRA's service before, during and after the installation of the FINDER, Mr Peng Haili, General Manager of Jinlijia, said: "TOMRA sent a qualified local service engineer who did an excellent job and made sure that our new processing line achieved its target sorting performance and that the new line began operation on-schedule."
The FINDER goes to work
The amount of scrap input to the FINDER varies from 1-4t, depending on clients’ diverse demands regarding product purity and throughput. If a high recovery rate and a high level of purity are required, normally it is necessary to lower the rate of throughput.
TOMRA’s FINDER sorting machine provides the crucial stage of final checking on Jinlijia’s improved sorting line. The shredded mixed-metal fractions are sent to the FINDER following the electro-magnetic sorting, drum-screen filtering and eddy-current separation stages. The FINDER provides the final check by sorting the remaining material in two steps. Step 1 separates all the remaining metal content (Zurik metal), including the scrap stainless steel, cables and wires, and some non-ferrous metals. Then the separated Zurik is returned to a reconfigured FINDER, where the operator can reprogramme the machine with simply one touch of a key, and the stainless steel is then separated from the metal scrap.
The overall rate of metal recovery can be at over 95%, after these two steps. The remaining waste is finally discarded or "dropped" from the line and contains less than 1% of metallic content. And the purity of the stainless steel can be at over 90%, without the use of manual separation.
Thanks to the FINDER sorting machine, Jinlijia’s non-ferrous sorting line now requires only two operators, making the complete sorting process essentially automated.
TOMRA’s FINDER sorting machine proved very stable in operation, following installation, and no failure or malfunction occurred. The FINDER sorting machine can maintain highly efficient operation and continuous sorting as long as sufficient power and compressed air are in steady supply. The TOMRA FINDER consumes only 4.3KW of power and provides a highly efficient sorting solution with low energy consumption and low emissions. As a result, overall operational cost was reduced by the installation of FINDER.
“TOMRA’s FINDER is a great sorting machine, combining high efficiency with high stability, resulting in energy-savings. It helps us reach the 100% performance we expected,” commented General Manager Peng Haili.
Maximising the benefits of the sorting operation
Jinlijia’s upgraded non-ferrous metal sorting line contains four eddy-current sorters and one TOMRA FINDER, with the objective of fully recovering the non-ferrous metal from the mixed scrap. With this new line, over the course of 12 months Jinlijia was able to make approximately RMB1.5 - 2 million in additional profit.
As well, if the FINDER is able to separate pure stainless steel from the non-ferrous mix, this eliminates the need for four manual pickers, saving Jinlijia an additional RMB200,000, within a 12-month timeframe. More importantly, the previous, manually-operated line was inefficient and lost not only insulated wire but also, following eddy-current separation, amounts of small-size stainless steel, along with copper (including uninsulated wire), aluminium, and some PCB material. But with the new, upgraded line, all of these materials can be recovered by the TOMRA FINDER, and both the recovery rate and operational efficiency have been significantly enhanced.
“The recovery rate and product purity were both enhanced tremendously after the installation of the TOMRA FINDER in our sorting line, making our operation much more profitable than before. The system effectively eliminated manual sorting in downstream processes and significantly enhanced profitability by generating purer end-fractions that then drove added value," said General Manager Peng Haili, as he summarised, in a very complimentary way, the value of the TOMRA FINDER.
TOMRA extracts more value from waste by continuously improving its sorting solutions
Currently, after the waste has been finally sorted by the FINDER, the remaining waste contains mainly non-metallic materials, such as plastics, foam, wood and rubber. These materials are no longer suitable for further sorting and recycling, in terms of value, according to JInlijia. However, TOMRA is still in communication with Jinlijia, with a view to the possible further recycling of the remaining waste, to make the best use of these resources. TOMRA is committed to finding a viable technical solution, one with sufficient return on investment.
In addition, TOMRA is in discussion with Jinlijia on the extraction of pure copper, aluminium and zinc from the currently sorted Zorba, in order to sell it separately on the market, thus further increasing the value of the materials and the prices of the end-products. If the purity of each metal can be significantly enhanced, they can be sold at almost the same price as the original material. By doing so, not only would operational efficiency be enhanced, Jinlijia could also achieve sustainable development, both for its own business and for the environment.