The selection suggestions for second-hand crushers are the focus of attention for many small and medium-sized mining enterprises. A sand and gravel plant purchased a second-hand jaw crusher to save costs. The initial investment was 40% lower than that of a new device. However, after three months of use, it was shut down for 15 days due to frequent malfunctions, and the cumulative maintenance costs exceeded the purchase price of the equipment. Eventually, a new device still needed to be replaced. It can be seen that a reasonable purchase of a second-hand crusher requires careful judgment. ​

With the rapid progress of society, the mining industry is also developing steadily, and the equipment used is constantly being updated and replaced. Some of the discarded crushers have been sent to the second-hand market. The price of second-hand crushers is very low, which attracts small-scale users. So, can second-hand crushers be bought or not? Here is a detailed analysis for you. ​

I. Potential Risks of Second-hand Crushers

1. Performance degradation and insufficient efficiency

The core components of second-hand crushers (such as jaw plates and the moving cones of cone crushers) are difficult to accurately assess the degree of wear and tear after long-term use. For instance, a second-hand jaw crusher that has been in use for five years may have a crushing efficiency 20% to 30% lower than that of a new device, and its processing capacity may drop from the originally designed 200 tons per hour to below 150 tons per hour, failing to meet the production capacity demands of the production line. After a small quarry purchased a second-hand impact crusher, due to severe wear of the plate hammers, the qualified rate of the finished product particle size was only 60%, far lower than the 90% of the new equipment, resulting in the product being unsalable. ​

2. Shortened lifespan and frequent malfunctions

The designed service life of a crusher is usually 8 to 10 years, and the remaining service life of second-hand equipment is often less than 50%. Key structural components (such as frames and spindles) may suffer from fatigue damage and are prone to problems like cracks and deformations during operation. A second-hand cone crusher at a certain mineral processing plant suddenly shut down after one year of use due to the expansion of hidden cracks in the frame. The repair cost was as high as 60% of the equipment's purchase price. In addition, the vulnerable parts of second-hand equipment (such as bearings and seals) are mostly approaching their replacement cycle. After purchasing the machine, funds need to be invested immediately for replacement, increasing the hidden costs. ​

3. Lack of after-sales service and maintenance difficulties

New equipment usually enjoys a free warranty of 1 to 2 years and professional technical support, while second-hand equipment has almost no after-sales guarantee. When the equipment malfunctions, users have to find maintenance personnel by themselves, and it also becomes difficult to purchase spare parts due to the old model. The second-hand impact crusher of a certain building materials company experienced rotor imbalance. As the original factory parts could not be found, non-standard modifications had to be carried out, which not only cost 30,000 yuan but also led to a further decline in equipment performance. ​

4. Component hazards and quality fraud

Some second-hand equipment sellers, in pursuit of profit, will replace inferior parts to cover up defects. For instance, if high manganese steel jaw plates are replaced with ordinary carbon steel ones and a wear-resistant layer is sprayed on the surface to disguise them as new parts, it is difficult to detect them in the short term, but their service life is only one third of that of the original parts. What's more, some people repair the broken frame by welding and then repaint it. Although it seems intact when purchased, it is very likely to break again after heavy load operation, posing a serious safety hazard. ​

Ii. Applicable Scenarios of Second-hand Crushers

Despite the higher risks, second-hand crushers still have purchase value in certain circumstances:

1. Short-term emergency use

When there is a sudden equipment failure on the production line and the delivery cycle of new equipment is long (for example, it takes three months to deliver a large cone crusher), second-hand equipment in good condition can be temporarily purchased to maintain production. Due to the sudden damage of a jaw crusher in a certain infrastructure project, a second-hand device that had been in use for one year was purchased as a transitional measure. Three months later, the new device was delivered, and the resale of the second-hand equipment only led to a loss of 5%. ​

2. Low-load test production

For small-scale experimental mines (with a daily processing capacity of less than 50 tons), low-cost second-hand equipment can be purchased to verify the processability of the ore. If the project is feasible, new equipment can be upgraded to reduce the initial investment risk. A certain prospecting enterprise purchased a second-hand jaw crusher for 50,000 yuan for testing. After confirming the quality of the ore, it invested in a new production line, thus avoiding blind investment. ​

3. A nearly new machine in excellent condition

Some enterprises, due to transformation or financial issues, will sell nearly new machines that have been in use for less than one year and have run for less than 1,000 hours. The performance of such equipment is close to that of new machines, but the price is 20% to 30% lower, and there may still be a portion of the original factory warranty remaining. When purchasing, it is necessary to verify the equipment's production date and operation records, and hire professionals to inspect key components. ​

Iii. Key Points for Selecting Second-hand Crushers

If it is indeed necessary to purchase a second-hand crusher, the following checks should be conducted:

1. Equipment traceability and inspection

Ask the seller to provide the original contract of the equipment, the factory certificate of conformity, and the maintenance record. Verify the manufacturer and give priority to choosing equipment from large manufacturers. ​

Hire a third-party testing agency to inspect the frame and spindle for cracks through ultrasonic flaw detection. Measure the wear of key components (such as the height of the jaw plate teeth and the thickness of the cone crusher liner), and assess the remaining service life.​

2. Test run to verify performance

Run the vehicle no-load to observe if there are any abnormal noises or vibrations (the amplitude should be less than 0.1mm). Test the machine with materials for more than one hour to check whether the output and the particle size of the finished product meet the requirements, and whether the motor current is stable (the fluctuation should be less than 5%). A certain buyer found that the actual output of the second-hand cone crusher they purchased was 40% lower than the nominal value because they did not bring the materials for trial operation, making it difficult for them to protect their rights. ​

3. Accessories and Maintenance support

Confirm the universality of the vulnerable parts and give priority to choosing models with a large market share (such as PE500×750 jaw crusher) to facilitate the subsequent purchase of spare parts. Agree with the seller on a 30-day warranty period and clearly define the responsibility for fault repair. ​