Apatite is the main source of phosphorous for the making of chemical fertilizers. While apatite is usually recovered from phosphate orebodies as the primary product of a mining exploitation, this paper documents the approach taken to produce a phosphate concentrate as a secondary product from the tailings of a niobium ore concentrator. The conventional desliming/flotation scheme used to process phosphate ores was tested and adapted to process one of the reject streams of a niobium concentrator in order to produce a salable phosphate concentrate. For that particular material, it was found that the reverse flotation of apatite yielded better results than the commonly used direct flotation of apatite. The recommended approach to produce the phosphate concentrate is desliming followed by reverse flotation of apatite and an acid leaching of the apatite concentrate to lower the MgO content below the specification for a phosphate concentrate. The obtained phosphate concentrate assays more than 32% P₂O₅ at a P₂O₅ recovery of 41%, which although low is found to be economic for the case of processing plant reject tailings.

中文翻译：

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从铌矿选矿厂的尾矿生产磷酸盐精矿

磷灰石是制造化学肥料的主要磷源。虽然磷灰石通常是从磷酸盐矿体中回收的，这是采矿的主要产品，但本文记录了从铌精矿尾矿中生产磷酸盐精矿作为副产品的方法。测试了用于处理磷酸盐矿石的常规脱泥/浮选方案，并使其适于处理铌选矿厂的废料流之一，以生产可销售的磷酸盐精矿。对于该特定材料，发现磷灰石的反向浮选比通常使用的磷灰石直接浮选产生更好的结果。推荐的生产磷酸盐精矿的方法是除泥，然后进行磷灰石的反向浮选和磷灰石精矿的酸浸，以将MgO含量降低到磷酸盐精矿的规格以下。所得磷酸盐精矿含量超过32％P₂ O ₅的P ₂ O ₅回收率为41％，尽管对于加工厂的废料尾矿来说，这很低，但发现是经济的。