Thermal & Chromite Sand Reclamation

• Thermal Reclamation Units
• Chromite Separation and Recovery Plant

• Reduction in New and Chromite Sand Purchase
• Reduced Dumping Costs

The foundry industry is under extreme pressure both financially and environmentally in the buying and disposal of sand, which is an essential element in casting production. Disposal by dumping is becoming increasingly expensive and even more difficult if the sand has Chromite contamination.

It is important that foundry’s optimise sand systems to help control their sand efficiently and minimise costs.  FTL is able to offer in addition to our range of primary mechanical reclamation, two systems for further treatment of sand to greatly reduce dumping costs:

1. Thermal Reclamation Unit
2. Chromite Separation and Recovery Plant

The FTL – Thermal Sand Reclamation unit comprises of a gas fired furnace followed by a two stage cooler, all operating on the fluidised bed principle.

Capacities range from 250kg/hr up to 4oookg/hr. 

Mechanically reclaimed sand from the mechanical attrition system is fed to a small receiving hopper. It is then fed into the thermal unit’s furnace body via a screw feeder passing through a vibrating screen to ensure that oversize material or sleeve materials are removed.

This screen also acts as a tramp metal removal system, in the case of non-ferrous applications. Provision can be made for additives to be introduced to the process if Alkaline Phenolic coated sands are to be reclaimed.

The FTL Chromite separation and recovery plant is a three stage process:

• Removal of ferrous materials
• Separation of Chromite
• Scrubbing and classifying of Chromite

The use of chromite for facing sand together with reclaimed silica backing sand will lead to a build-up in the levels of chromite in the reclaimed backing sand. These levels can frequently build-up to 15-20% causing problems with the reclamation process, increased resin and catalyst/hardener usage and increased fettling costs due to poor casting surface finish.

In addition, the high cost of new chromite purchases and the ever increasing dumping costs further highlights the need to recover the chromite from the reclaimed sand for reuse, reducing the costs.

The separation of chromite from contaminated reclaimed sand can be achieved by the use of a rare earth magnetic drum, reducing chromite contamination levels to below 2-3% and producing a reclaimed chromite with a purity in excess of 90%.