LAND Instruments have supplied to the mineral processing industry such as Cement and Roadstone Industry throughout the world with temperature measuring equipment for over 60 years. All our products are designed to the highest standards of quality and reliability to ensure accurate measurements under plant operating conditions. If your specific area of concern is not covered here, our engineers will be pleased to discuss your requirements with you.
Mineral Processing – Cement
LAND have supplied the Mineral Processing Cement Industry and OEM’s throughout the world with temperature measuring equipment for over 60 years. All our products are designed to the highest standards of quality and reliability to ensure accurate measurements under plant operating conditions.
The schematic diagram below illustrates typical features of a cement works. The areas highlighted offer measurement reference points and offers the best choice of instrument, where LAND’s infrared thermometry know-how can really benefit you. If your specific area of concern is not covered here, our engineers will be pleased to discuss your requirements with you.
Kiln Shell Temperature
The early detection of hot or cold spots is vital to avoid costly maintenance or an unplanned shutdown. Continuous monitoring of the Mineral Processing kiln shell along its length day and night will provide the earliest possible indication of potential problem spots.
Sighting tubes of different lengths are installed in various kiln positions – the radiation thermometer accurately measures the temperature at the end of the tube once very kiln rotation. Depending on the thermometer location either the solids (for product quality) or the gases (for kiln efficiency) within the kiln can be measured.
Measurement of the temperature in the kiln burning zone is vital for maintaining both product quality and kiln efficiency. A 2-colour (ratio) thermometer is used to overcome the inherent problems of dust etc. which obscure the thermometer sight path. This system can be applied equally to both wet and dry processes.
To safeguard against either fire or belt burn out the clinker in the bucket elevator must be sufficiently cooled prior to reaching the rubber conveyor. A thermometer used in a closed control system monitors the temperature of the clinker before it reaches the conveyor. This system sets the cooling levels and improves operating efficiency.
The schematic diagram below illustrates the essential features of a typical Mineral Processing roadstone plant. The areas highlighted offer measurement reference points and the best choice of instrument, where LAND’s infrared thermometry know-how can really benefit you.
If your specific area of interest is not covered here, our engineers will be pleased to discuss your requirements with you.
Drier Exit Chute
A radiation thermometer is normally positioned in the drier exit chute to monitor the temperature of the aggregate as it leaves the drier. Utilizing a radiation thermometer permits closed loop control to set burners in the drier minimising fuel wastage and maximising product quality.
When using the batch process, automatic burner control is not possible. Knowledge of the hot stone temperature and its subsequent effect on the binder and filler temperature is a useful aid to process control. Once the material is in the mixer it is not possible to make temperature adjustments. Measurement here does however, permit rejection of a single batch if it falls outside the specified temperature limits, avoiding contamination of acceptable material.
With the high level of continuous production in the mineral processing, any slight fluctuation in the final mix temperature can result in batch rejection. Measurement at the discharge chute can be fed to a chart recorder or linked to an automatic burner control system using a suitable controller.
For large capacity drum mix plants, coated roadstone is stored in heated storage bins, often overnight. A Roadstone thermometer positioned at the exit door monitors temperatures of the discharged material to minimise the risk of batch rejection, due to it being out of the specified temperature range.
One final check can be made here on the temperature of the product. On-site quality engineers can make spot checks using portable equipment. Failure to maintain quality control here could lead to uneven road rolling, premature wear and subsequent expensive repair.