Tungsten carbide (WC) is the most important tungsten compound, and the main component of WC-Co cermet composites. WC-Co are widely used engineering materials due to the combination of high hardness and strength of tungsten carbide with the toughness and plasticity of the metallic binder. The direct synthesis of WC from tungsten concentrate containing ∼70% WO₃ has been achieved by carbothermic reduction. Mineral/carbon black mixtures were prepared by planetary ball milling and subjected to annealing at 1150 °C in flowing Ar. Specific leaching treatments have been developed to remove foreign phases and obtain pure WC powders. This new process allows about 50% energy saving, −34% CO₂ emissions, and significantly lower amounts of industrial waste, with respect to the classical hydrometallurgical tungsten extraction and subsequent pyrometallurgical WC synthesis, widely used in tungsten industry. WC powders obtained by carbothermic reduction of the mineral were employed to prepare sintered WC-8 wt %Co samples that showed high density (>99%), hardness (1490 HV), and toughness (14.6 MPa·m^1/2). These findings demonstrate, for the first time, that the carbothermic reduction of tungsten concentrates does represent a viable process for energy efficient and sustainable synthesis of WC powders to be used in the production of cemented carbides.

中文翻译：

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用于硬质合金碳化钨制造的 WC 粉末的绿色合成

碳化钨（WC）是最重要的钨化合物，是WC-Co金属陶瓷复合材料的主要成分。由于碳化钨的高硬度和强度与金属结合剂的韧性和塑性相结合，WC-Co被广泛使用。已经通过碳热还原从含有~70% WO _{3 的}钨精矿直接合成WC 。通过行星式球磨制备矿物/炭黑混合物，并在流动的 Ar 中在 1150 °C 下退火。已经开发出特定的浸出处理来去除外来相并获得纯 WC 粉末。这种新工艺可节省约 50% 的能源，-34% CO ₂与广泛用于钨工业的经典湿法冶金钨提取和随后的火法冶金 WC 合成相比，排放量和工业废物量显着降低。通过对矿物进行碳热还原获得的 WC 粉末用于制备具有高密度 (>99%)、硬度 (1490 HV) 和韧性 (14.6 MPa·m ^1/2 ) 的烧结 WC-8 wt % Co 样品。这些发现首次表明，钨精矿的碳热还原确实代表了一种可行的方法，可用于生产硬质合金的 WC 粉末的节能和可持续合成。