Meishan Iron Mine Tailings High-pressure Enrichment Process,

To reduce environmental pollution and to increase thickening density of tailings have become the most important technical challenges facing the dressing scientific research work of Meishan Iron Mine. The high-pressure thickening process may solve these problems. To increase underflow density of the tailings mainly depends on the application of the advanced high-pressure thickening technology, selection of flocculent and appropriate control influencing flocculating settling factor. The paper mainly aims to research on the ways to improve the settling property of the tailings, to research on the main factors affecting flocculating settling and to analyze the settling thickening mechanisms of a general thickener and a high-pressure deep cone thickener, so as to realize high density thickening and transport of the tailings.The paper has four main research contents: (1) The static settling test is used to research on the ways to improve the settling property of the tailings, selection of flocculent types, determination of flocculent dosage range, appropriate flocculating thickening conditions and effect of temperature on the settling property. It is determined that the anion polyacrylamide is an effective flocculent for Meishan tailings. (2) The research on temperature to compressing time shows that with enhancement of density, the temperature Kc enlarges, the effect of the temperature on the compressing time is significant. With increasing of density, the compression becomes difficult. The Kc value in the temperature section of 10°C-18°C is the largest. It shows that the temperature has a significant effect on the compressing time in thistemperature section. The compression becomes difficult in the temperature section of 6°C-10°C, therefore, the Kc value is small. The compression becomes easy as the temperature is above 18°C, therefore, the Kc value is also small. (3) The test results of a part of Meishan tailings by using the φ1.5m high-pressure deep cone thickener show that the high-pressure deep cone thickener has high capacity. The stable underflow density may be obtained as the high-pressure thickener and the flocculating thickening process are used. The practice proves that the improved thickening process of using the high-pressure thickener and 4φ 50m thickener to treat Meishan tailings has achieved good results. The underflow density reaches 45% and solid content in the overflow is ≤ 300×10~-6. (4) The fluid mechanics is used to research on the settling theory of solid particles in different zones of the general thickener. The two-phase flow movement of the liquid-solid phase of the high-pressure deep cone thickener is analyzed. The paper researches on the adsorption behaviour, adsorption process and flocculating mechanism of high molecular flocculent on the solid particle surface of the tailings.