As more foundries evolve into machining processes to add value to their products, the issue of what to do with machine swarf and chips becomes more and more important. Toll them out or recycle internally?

Tolling out can be a viable way to deal with small volumes of chips but there comes a point where this is effectively giving money away and directly recycling the material into the melting furnace can give both economic and quality advantages over outside processed chips.

But the payback is very dependent on the volume of chips, the type of melting processes, alloys used and quality of final product need to be considered. This has traditionally proved uneconomic for the smaller foundries and it has been easier to toll their machine chips to outside recyclers. This doesn’t have to be the case and the benefits in terms of metal cost savings, control of metal incoming quality and overall costs savings can now be achieved.

So where is the point where recycling becomes cost effective and what are the process options available?

Briquetting; the simplest system entails compressing chips into solid briquettes. These can be melted in dry hearth furnaces normally up to 5- 10% of melting capacity. Beyond this the dross build up can be detrimental to normal melting. In wet bath melting the briquettes must achieve a density in excess of 2,350 kg/m³ (~147 lbs/ft³) or briquettes will float and create dross.

Direct melting; Vortex submergence ; the most efficient method where chips are submerged in a vortex created by pumping the molten metal through a circular shaped vortex block. The block and pump are installed in a pocket onto the holding bath and creates circulation of the melted chips to improve temperature uniformity and homogeneity of the molten metal.

Capacity is normally 10% of the available molten bath volume

SINC Thermal has set out to create the best options for the small foundry in combining proven technologies in new and innovative ways to improve efficiencies and economics.

Using proven equipment from reputable suppliers in the US and overseas we aim to offer the best “world class” systems to help our customers become the best.

Furnace technology

We can offer a range of melting and holding systems from simple crucible furnaces to highly efficient shaft-melting technology.

Chip melting

SINC Thermal and G&P have worked with industry proven technology from Lotuss system from Pyrotek, the MMEI ScrapEater or the Coriolis system from High Temperature Systems. In every case you get world class technology with a proven track record.

Chip preparation

Collecting, preparing and dispensing the chips to the chosen melting system is always a critical part of the process and impacts production as well as melting operations.

Recycling of cutting fluid / cleaning of chips Transport from source to melting furnace

Containment / recycling of emissions from melting process.

These are all critical components of an efficient and economic process.

SINC thermal can assist in this area with technologies for the smaller foundry that can make this process simpler and more effective.