Increase in crushing productivity

Increase in crushing productivity

20% increase in productivity and more uptime at Minermix

Minermix quarry, located in the countryside of Brazil’s state of São Paulo, has been using Metso’s latest crushing technology since January 2016. Lifetime of the crusher’s linings is at least 30% higher, according to the company.

Boosting recrushing operation and improving quality

The Minermix Mineração unit in Capivari, a city in the state of São Paulo, is the newest of the three quarries owned and operated by Brazil’s Extrabase group. For the past seven years, the facility has had a nominal production capacity of 200 000 metric tons per month, employing a processing plant that is equipped for primary and secondary crushing, followed by tertiary stage crushing. With a single stockpile – unlike the company’s other quarries, which have two stockpiles each – the tertiary stage crushing operation at the Minermix Capivari facility required a boost.

At the same time, Minermix wanted to reduce the presence of dust-like material in the production of sand from gravel; manufactured sand is a product directed primarily to concrete plants, and the presence of excessive quantities of rock dust (fines) is a problem. Minermix also intended to ensure the highest possible degree of standardization of this material, which, considering the need to continually adjust the equipment used is a constant challenge. The operation could, in the company’s assessment, be more productive and require fewer adjustments by the equipment operator.

Increase of 20% in productivity 

The Minermix crushing plant in Capivari is fed with basalt mined from a site located approximately one kilometer from the facility. The primary crushing phase includes a Metso Nordberg® C125™ jaw crusher, followed by secondary crushing with a Nordberg® HP400™ cone crusher. All the material requiring further processing is crushed in two parallel tertiary crushing stages. Until January 2016, this job was performed by two HP4s that had been installed since the beginning of the quarry’s operation in 2010. Today, one Metso MX4™ Multi-Action cone crusher works alongside the original HP4. Number 4 stands for the power rating that is 400 horsepower.

According to Minermix Mineração Supervisor José Nilson, Metso’s MX4 cone crusher was installed with the complete support of Metso (including training of the operator), and, since its start-up, has demonstrated an increase of 20% in the productivity. In José Nilson’s assessment, the gain in productivity may be as high as 30% with supplementary adjustments.

The supervisor credits this improvement mainly to the fact that the equipment enables adjustments while operating at full load capacity or, in other words, without the need to shut down the equipment, and its use at maximum power. “The equipment reaches 95% and, when it reaches peak production, the equipment itself makes the adjustments to balance production,” Nilson says. The stability of production has also enabled a 5-10% reduction in the production of rock dust, an unwanted byproduct in the production of manufactured sand used by concrete plants. “It may not seem like much, but the reduction has a notable bearing and impact on daily production,” explains José Nilson.

More uptime with the patented Multi-Action technology

MX4 is based on the patented Multi-Action crushing technology that combines the piston and rotating bowl into a single crusher. The way it has been designed, the crusher provides the maximum utilization of the wear parts leading to extended maintenance intervals.

The MX4 works throughout the day, self-adjusting the crusher opening/setting or power to our specifications,” José Nilson adds. This kind of underload dynamic adjustment means more uptime, as it is carried out while crushing. An audible alarm informs the operator that the temperature and pressure conditions, the oil level, etc., are in conformity with previously established parameters.

Nilson notes that the MX4 automation is another feature that has improved the operation overall. “The operator turns on the equipment with a single touch of the crusher automation’s screen, which also enables the crusher operation to be monitored throughout the day and gives us a final report when the equipment is turned off,” he details.On a weekly basis, the MX4 crusher is calibrated by initiating an automated procedure that takes five minutes at most. Calibration determines the degree of wear in wear parts and adjusts

the settings based on those findings. This assessment also enables the correction of any parameter that is not aligned with what has been pre-established by Minermix. The replacement of wear parts is performed after around 1200 hours of operation, which is more than one-third longer than before. Lifetime of the crusher’s linings is at least 30% higher, according to the company.

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