Kazakhstan Plans to Boost Copper Output by Nearly 25% (Update1) 

March 17 (Bloomberg) -- BHP Billiton Ltd., the world's biggest mining company, halted production at its Kwinana nickel refinery in Western Australia on March 15 because of a lack of hydrogen gas.
&quot;We have a hydrogen plant that has experienced some problems,&quot; spokeswoman Amanda Buckley said today in a phone interview from Melbourne. &quot;We normally have back-up hydrogen available from another source. That wasn't available.&quot; She declined to give a forecast on when the refinery will reopen or whether shipments will be affected.
BHP is working on maintenance at the refinery while production is halted, Buckley said. Hydrogen is a key ingredient in the process of refining nickel, a metal used to strengthen stainless steel.
The Melbourne-based company's Nickel West operations in Western Australia, which include the Kwinana refinery, a smelter at Kalgoorlie and a concentrator at Kambalda, produced 59,400 tons of nickel concentrate in the six months to Dec. 31, Buckley said.
The price of nickel in London has more than doubled in the past year on surging demand in China. BHP's Sydney-traded shares closed 1.3 percent higher at A$43.30. 
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