Codelco to restart projects beginning next week

Chile’s state-run miner Codelco, the world’s largest copper producer, said on Thursday it would restart operations and projects it had suspended due to the coronavirus pandemic, beginning next week.

The miner had been forced to delay several mine expansion projects as cases of the virus spread through its operations, though it has largely maintained output during the pandemic.

The company said in a statement workers would soon return to the new underground portion of its sprawling Chuquicamata mine, and that the operation’s smelter and refinery, shut down amid the worst of the outbreak, would soon reboot.

The company had also delayed work on a new level at its century-old El Teniente mine, and said that project would restart shortly.

The coronavirus outbreak caught Codelco in the midst of a 10-year, $40 billion initiative to upgrade its aging mines, which have suffered in recent years from falling ore grades.

The state-run miner, which has faced heavy scrutiny by its unions of its handling of the pandemic, included a long list of safety measures it planned to implement to stave off further outbreaks at its operations.

Among them, it said it would not use a regional airport near Chuquicamata and that it would test all workers in their city of origin prior to their shifts.

Chile has been especially hard hit by the coronavirus, registering more than 360,000 confirmed cases and nearly 10,000 deaths.

Jaw plates include fixed jaw plate and swing jaw plate, which are the main jaw crusher wear parts. They need to exchange very regularly. When & How to change jaw plates?

When to change jaw plates?

There are two situations need to change the jaw plates.

1. In order to prevent damage to the crusher parts, jaw plates need to be changed before they are worn through. Different kinds of jaw crushers have different situations. In some kinds of jaw crushers, jaw plates with a wedge retention design can wear to a thickness of 20-25 mm until they must be changed; In some other jaw crushers, jaw plates with locking wedges in the back can wear to a thickness of 60-65 mm until they must be changed. When to change jaw plates? It based on your jaw crusher wedge retention design.
2. Economic benefits and costs. After a long time of running, productivity will decrease because of the wear of jaw plates. So we need to calculate the ratio of economic benefits and cost. If the loss can cover the jaw plates price, we need to consider to change jaw plates.

How to change jaw plates?

Jaw crusher wear parts need to be changed following the correct procedures to avoid risks. Different kinds of jaw plates need different ways to change jaw plates.

One-piece jaw die rotation and replacement

• After a new jaw dies installation, rotate the single-piece jaw dies when 30% of the tooth profile is worn.
• Rotate a second time when the tooth profile at the bottom of the jaw die is completely worn.

Two-piece jaw die rotation and replacement

• Worn out jaw dies are removed from the bottom of the crushing chamber.
• Work hardened upper jaw dies are installed at the bottom of the crushing chamber.
• New jaw dies are installed at the top of the crushing chamber.

@Nick Sun    NICK@XZHUAGANG.COM