A cone crusher can be used to crush a wet gravel-sand mixture with a moisture content of up to 12%, with the feed size not exceeding 85% of the receiver, whilst reducing the feed rate by 15–20%; for clay content up to 5%, cleaning is required every 8 hours.
Yes, it is possible to crush a damp mixture of gravel and sand using a cone crusher; according to the results of field tests, no significant reduction in the equipment’s performance is observed when the moisture content of the raw material is up to 12%.
The cone crusher has a closed crushing chamber with smooth working surfaces, which reduces the likelihood of damp raw materials sticking compared with jaw crushers; according to engineering tests, at a moisture content of 8%, the adhesion coefficient on the surfaces of the crushing cones is no more than 3% of the total mass of the feed material.
To ensure the stable operation of a cone crusher with a wet mixture of gravel and sand, the permissible feed particle size must not exceed 85% of the equipment’s feed opening size, in accordance with the official specifications of manufacturers of medium and fine cone crushers; if this limit is exceeded, frequent jamming of the crushing chamber occurs, even at standard moisture levels.
When processing a damp mixture of gravel and sand, it is recommended to reduce the feed rate of the raw materials by 15–20% from the nominal value specified in the equipment’s technical specifications; these figures represent an engineering reference range verified at road construction sites in regions with a humid climate.
The table below compares the key performance indicators of a cone crusher with varying moisture content in the gravel and sand mixture; all data are based on the results of field tests carried out on standard secondary crushing equipment: with a moisture content of up to 5%, operational stability is 99%, the yield percentage of the standard fraction is 96%, and the risk of jamming is less than 1%; at a moisture content of 6–12%, operational stability is 92%, the yield of the standard fraction is 88%, and the risk of jamming is 4%; at a moisture content above 12%, operational stability is 71%, the yield of the standard fraction is 67%, and the risk of jamming is 18%.
The first question is: can a standard cone crusher be used to process a wet mixture containing clay impurities? The answer is yes, provided that the volume of clay particles does not exceed 5% of the total mass of raw material, according to the results of production tests. The second question is: how often does the crushing chamber need to be cleaned when processing a wet mixture of gravel and sand? The answer is that, provided the recommended feed rate is observed, cleaning is required once every 8-hour shift; these figures are engineering reference values. Third question: Does the moisture content of the mixture affect the size of the final fraction? Answer: Provided that the permissible raw material parameters are observed, the deviation of the final fraction size from the nominal value does not exceed 7%, according to the results of control measurements at work sites.
