For crushing high-quartz basalt, choose jaw crushers with a compressive force of ≥350 MPa, manganese jaw plates, an appropriate jaw stroke, chamber angle, low shaft speed and a uniform feed rate.
For crushing basalt with a high quartz content, jaw crushers with a compressive strength of at least 350 MPa, as specified in the manufacturers’ official specifications, should be selected
The most important parameter is the compressive force of the crushing jaw, which must correspond to the compressive strength of the raw material. Basalt with a quartz content exceeding 20% has a compressive strength ranging from 320 to 400 MPa, according to engineering reference values. The stroke of the movable jaw is also important; for highly abrasive materials, a stroke in the range of 15 to 30 mm is recommended, based on the results of industrial trials
Crushing jaws designed for use with quartz-bearing basalt must be manufactured from steel with a manganese content of at least 12%; in accordance with official component specifications, such materials exhibit minimal wear when in contact with abrasive raw materials. According to the results of field tests, the service life of such components is 40–60% longer than that of standard cast-iron parts. It is also recommended to select a crushing chamber design with a jaw angle of between 18 and 24 degrees, based on the calculated values from engineering methods, which prevents hard chunks of raw material from becoming jammed
When working with basalt with a high quartz content, it is not recommended to set the eccentric shaft speed above 280 revolutions per minute; according to the results of practical tests carried out at quarries, exceeding this limit leads to an increase in vibrational loads on the equipment frame on 30% or more. It is also advisable to maintain a steady feed rate of 80–85% of the plant’s rated capacity, in accordance with the manufacturers’ official recommendations; this helps to prevent overloading and uneven wear of the crushing surfaces
The table sets out the verified specifications for equipment suitable for the specified task: compressive strength from 350 to 500 MPa according to the manufacturers’ official specifications; movable jaw stroke from 15 to 30 mm according to engineering reference values; and the material of the crushingis steel with a manganese content of 12 to 14%, according to official component specifications; the crushing chamber angle is 18 to 24 degrees, based on calculated values; the eccentric shaft rotational speed is 220 to 280 revolutions per minute, based on the results of industrial trials
Question 1: Can a standard jaw crusher be used for basalt with a high quartz content? Answer: Standard units designed for a compressive strength below 350 MPa exhibit 2to three times higher, according to field test results; therefore, their use is not recommended. Question 2: How does the quartz content affect the selection of crusher parameters? Answer: As the proportion of quartz in basalt increases by every 10%, the equipment’s compressive strength must be increased by at least 50 MPa, according to engineering calculations. Question 3: How can wear on the crushing elements be reduced when working with such raw material? Answer: It is recommended to avoid allowing pieces of raw material larger than 80 1 TP 3 T of the feed opening’s width to enter the crusher, in accordance with official manufacturers’ recommendations; this reduces the load on the jaw plates by 25–30%, according to test results
