China’s state-run iron ore buyer has told major steelmakers and traders to temporarily halt purchases of all new BHP Group cargoes, escalating a pricing dispute that risks upending one of the mining giant’s most important trading partnerships. China Mineral Resources Group Co., created by Beijing to bolster the country’s sway in the global iron ore trade, asked domestic buyers this week to suspend purchases of any dollar-denominated seaborne cargoes from BHP, people familiar with the matter said, asking n ...