The role of shredders and balers in recycling

Balers and shredders are important pieces of equipment for preparing various materials for recycling, and purchasing the right machinery will provide long term benefits.


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Recycling
 
October 22 2020
 
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Shredders and balers are important pieces of equipment for preparing various materials for recycling, and purchasing the machinery that is best suited for a company’s operations is of significance as it could aid or hinder the operations in the long run. It is a worthy investment and some major recyclers in the region provide insights on different aspects related to baling and shredding machines, in an interview with Swaliha Shanavas.  

RKG International FZC processes and exports both ferrous and non-ferrous metals, handling an average of 15,000 tonnes per month from the UAE besides the materials sourced from around the world. In line with its processing requirements, the company has installed necessary equipment at its facility including two shredding machines, one baling machine, four excavators, a JCB, two forklifts, and has recently imported a new shearing machine, notes Rajesh Agarwal, Managing Director, RKG International. He says they had taken over a sick shredder unit and completely refurbished and revamped the whole unit with the help of their in-house experts.

Speaking about their operations in Saudi Arabia, Engr. Salam Sharif, Chairman Sharif Metals Group, says, “Our facilities handle 25,000 tonnes per month, which includes HMS, LMS and shredded steel that is generated either by manufacturers, service industries, construction and demolition sites and steel fabricators, or end of use material.” The company is engaged in the collection and processing of nonferrous and ferrous scrap metals from industrial, commercial and retail sources; collection of end-of-life vehicles for dismantling and shredding in KSA; the sale of various grades of prepared scrap to diverse domestic and export customers around the world.

Engr Salam, who also serves as Chairman, Ambassador Committee BIR and Hon. Chairman BMR, notes that due to rapid urbanisation over the past two decades, (though there was a drop during 2008-2009 crisis and covid-19) huge material generation served as a major feedstock for steel mills for heavy gauge steel structures or steel bars. A combination of automobile scrap and household end of life material form the main feedstock to shredders and later on to steel mills.

“Considering the high standard of living in KSA, automobiles have more than an average turnover, where after about 5-7 years lifecycle lots of vehicles end up in dismantling facilities for reusable spare parts, which forms a secondary market called “junk yards”. The last resort will be the auto shredder facilities, which shred the entire vehicle bodies into 2 to 3 inches pieces, separating non metallics fully through its process,” he says, adding that such steel scrap is of high density that provides high yield to steel mills with above average melting recovery, compared to baled material. “The steel mills will be more comfortable and have better perception of shredded material fearless to closed containers, which may cause huge explosions in the Hammermill, and safety hazards when oil is contained in a closed container,” he remarks.

Chiraag Kisani, Commercial Manager, Zenath Paper Traders, owned by Veena Kalwani One Person Company LLC, says they have installed three automatic baling machines at their facilities, with an overall capacity to handle over 200 tonnes per day and more than 5000 tonnes per month (including OCC 50%, SMIX 30% and other grades 20%).

One of the machines has a capacity of over 150 MT per day and can be used for all kinds of recovered paper, he says. A second machine, which has been in operation for many years has a capacity of around 60 MT, while the third baler has a capacity base of 50 MT per day. “The balers we have installed are highly efficient, and the average bale weight is high as compared to other machines. They come with more safety features and the system is also computerised,” says Kisani.

Selecting the right equipment

In Agarwal’s view, many factors need to be taken into account including the type of material that a company plans to bale or shred, and the amount of material that is currently recycled vs. the realistic future material forecast. The usability of the machine needs to be determined, and the amount of metal that needs to be shredded along with the frequency of work needs to be considered. The purchasing team must also exercise good judgment when selecting replacement components for both maintenance and production, which plays a very important role in increasing the productivity.  

Further, setting up a baling or shredding operation involves selection of the right location, also based on the availability of raw material in the area, availability of the spare parts and access to regular maintenance of the machinery. “It is important not only to focus on the upfront price of the machinery, we need to consider the running costs such as power, operation, servicing and maintenance as well as additional costs involved. The horsepower capacity of the shredder will help us in understanding the amount of metal that we can shred at once. If we are dealing with loads of metal every day and that too in bulk, then going with metal shredders of high capacity is always advisable. This will help us save a lot of time and get our work done with perfection,” he explains.

Challenges  

Maintenance has an important role following the purchase of machinery. The main challenge RKG faced was the non-availability of maintenance personnel with adequate knowledge to fix the machinery and spare parts. “If one could improve the reliability, product quality will improve, which in turn increases capacity and profitability will follow,” says the managing director.

“Considering this as the main challenge, we set up our own trained technical team and a workshop to ensure regular maintenance of the machinery. The objective was preventive maintenance, not quick fix of breakdowns. Planning and scheduling are essential parts of effective maintenance. The workforce has the training and skills required to complete their assigned duties in the department,” he emphasises.

Kisani says they are able to handle incoming material at a reasonable pace and produce material with maximum weight, which is an advantage. “But we do face challenges mainly in terms of maintenance and spare parts availability (electric and mechanical parts are not available in the local market). We need to order and wait for long periods of time for certain spare parts, and there is a need for AMC and follow up through the dealer,” he underscores.   

Key benefits

Shredded scrap is simpler and gives a thick blend when mixed with heavy and light material. The ferrous and nonferrous as well as other materials are automatically segregated through magnetic separation, which is hassle-free, notes Agarwal, adding that shredders don’t require intensive care and are easy to maintain. The design of the shredding machine is flameproof, so it can sustain enough mechanical damage. And the amount of torque that is used in order to process lightweight scrap and bulky scrap can be controlled with the use of a good shredder.

“Metals shredded using a shredder help improve furnace feeding so that the efficiency of re-melting can be increased. The time proficiency of the shredder is exact, and the crude materials are offered in the fastest period. The scrap we shred at RKG meets ISRI specification ISRI211 and ISRI210. It’s the best quality and there is a high demand for this material in the local and international market, which is widely used in furnaces,” the MD comments.   

Engr. Sharif highlights numerous advantages of shredding as compared to other processes:

The size, shape, density and composition of shredded ferrous scrap bring cost benefits to steelmakers and foundries owing to savings in time and in resource and energy use through reduction in CO2 emissions in comparison to sheared or baled scrap. Electric arc furnaces can use 80-90 percent shredded scrap. As compared to other scrap types, using shredded ferrous scrap as infeed in steelmaking process reduces overall costs and increases meltshop productivity, in some cases, the direct proportion to the amount of shredded scrap added to the charge mix.

Melting times are reduced, increasing electric arc furnace (EAF) efficiency and therefore electrode and refractory lifespans. The shredding of scrap enables improved quality control, controlling among other factors the residual copper content and preventing radioactive presence. Shredded scrap commodity has high density above 0.9 tonnes/m3 and the unwanted material (soil, plastic, etc.) is kept below 2 percent, maybe as low as 0.75 percent. Slag production is reduced to a great extent, leading to a higher productivity.

Shredded scrap brings benefits to the scrap yards as the handling efficiency by grab or by conveyor belt is almost twice that of sheared or baled scrap in terms of tonnes handled per hour. Faster loading times are possible for inland water and deep-sea transportation in comparison to other scrap types; furthermore, the risk of damage to the vessel hold is lower if shredded scrap is loaded first. “I would like to emphasise the fact that shredded steel process gives the end of life materials a new life, which is a perfect example of circular economy phenomenon,” he concludes.

 

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