Odisha state is the major reserve of the chromite ore. Due to the extensive applications, high-grade chromite ore is getting depleted day by day. Now it is a challenge for the industry to utilize these low-grade ores and tailings. Several attempts were taken to upgrade the low-grade chrome ores and tailings using different gravity separation methods, magnetic separation methods, flotation, etc. But all the techniques have limitations for handling these ultra-fine chrome ores. Selective flocculation process can be one alternative method for upgrading the ultrafine chromite (< 37 µm). Mineralogical analysis reveals that ultrafine chromite tailing (< 37 µm) is enriched with ferruginous phase. Causticized starch of wheat origin was identified and used for flocculating. Selective flocculation performance due to change in different operating parameters such as dispersant dose, pH and flocculant dose was studied. Result shows that Cr₂O₃ (%) increases to 31.08 (%) with Cr/Fe > 1 from a feed grade of 16.36 (%) Cr₂O₃ with 0.36 Cr/Fe ratio. FTIR analysis reflects selective adsorption of the flocculant mineral surface.

奥里萨邦是铬铁矿的主要储量。由于广泛的应用，高品位的铬铁矿矿石日趋枯竭。现在，利用这些低品位矿石和尾矿对行业来说是一个挑战。进行了几次尝试，分别使用不同的重力分离方法，磁选方法，浮选法等对低品位铬矿石和尾矿进行升级。但是，所有技术在处理这些超细铬矿石方面都存在局限性。选择性絮凝工艺可以作为提纯超细亚铬酸盐（<37 µm）的一种替代方法。矿物学分析表明，超细铬铁矿尾矿（<37 µm）富含铁质相。鉴定出小麦来源的苛化淀粉并用于絮凝。研究了由于不同操作参数（例如分散剂剂量，pH和絮凝剂剂量）的变化而导致的选择性絮凝性能。结果表明铬Cr / Fe> 1时₂ O ₃（％）从进料品位16.36（％）Cr ₂ O ₃（Cr / Fe比为0.36 ）增加到31.08（％）。FTIR分析反映了絮凝剂矿物表面的选择性吸附。