We have more than 40 years’ experience processing, blending and supplying combinations of our high quality bentonite binders and lustrous carbon formers to the global foundry industry.
Blends may also include processed carbon and lustrous carbon formers further improving casting surface quality; optimizing molding sand performance and minimizing additions.
Blend formulations can be individually tailored to suit specific customer requirements.
Use of blends often called “Premix” has several advantages. Addition of bentonite improves the flowability of pulverized Sea coal allowing a more accurate dosage in the mixer due to the greater volume added.
The main reason for application of a blend is safety during transportation and storage. Products classified as dangerous due to their sensitivity and tendency for self-ignition require specialist transportation and safety measures during storage with products classified as explosive demanding costly ATEX safety installations in the foundry.
The Graph below shows the results from samples of coal dust and a 70/30 bentonite/coal blend. The samples are heated in the center of a ventilated oven at 140 degrees centigrade. The sample is considered to be an explosion risk and with a high probability of self-ignition if the temperature of the sample reaches 200 degrees. It can be seen that the blended product despite heating for 23 hours never reaches a temperature greater than 170 degrees C. The bentonite and coal mix cannot be classified as dangerous.