Copper’s powerful rally close to $10,000 a ton is facing a test as buyers in China, the world’s biggest market, balk at prices near their highest in two years. The metal has surged in recent weeks on investor optimism over a recovery in global manufacturing and the prospect of tightening mine supplies. But skeptics have pointed to weakness in China — including what they say is a growing reluctance among the country’s copper fabricators to accept higher levels. Fabricators have struggled to pass on higher costs to their customers, forcing them to rein in purchases since March, Wang Wei, general manager at major copper ... (full story)