American companies are grappling with a shortage of critical minerals used in daily operations despite China easing some of its export controls, according to industry insiders.After Beijing and Washington agreed to a so-called trade truce last November, the Ministry of Commerce issued a notice suspending a ban on shipments of gallium, germanium and antimony to the US for one year.But China’s dominant position in the global market for these vital raw materials, including heavy rare earths,...