Iron Ore Wastewater Treatment Process

Iron ore wastewater is also a relatively common type of wastewater in the water treatment industry, and can be divided into two main categories: mining wastewater and operational wastewater.

Chemical used: polyacrylamide

Processing procedure: First, add the solid granular polyacrylamide to water to dilute it. The concentration should be between 0.1% and 0.3%. Stir continuously to ensure complete dissolution (for example: to dissolve one tonne of water, add approximately 1–3 kg of polyacrylamide; to dissolve three tonnes, add 3–9 kg; and so on). It is important to note that the reaction tank must not be made of iron. Stainless steel or plastic are preferable. Under normal conditions, dissolution takes approximately one hour. During this period, stir continuously at a constant speed. If the water temperature is low in winter, the stirring time should be extended; however, the stirring speed must not exceed 300 revolutions per minute, as this could damage the flocs in the water and impair the water purification effect. Once fully dissolved, the polyacrylamide is then continuously fed into the iron ore wastewater via a valve or controller. Continuous stirring must be maintained to ensure thorough mixing, which is essential for achieving optimal flocculation, adsorption, sedimentation and water purification.

Common issues encountered in iron ore wastewater treatment and their solutions.

Issue 1: Poor flocculation results after adding polyacrylamide.
Causes: Firstly, verify that the correct type of polyacrylamide has been selected. Secondly, the dissolution time in the water may be insufficient. If the PAM has not fully dissolved in the water, the flocculation effect will be poor. Thirdly, consider the dosage of polyacrylamide. If the dosage is too low, there will be no significant reaction with the suspended particles in the wastewater. If the dosage is too high, the flocs formed will not settle.

Issue 2: Filter cake from iron ore wastewater. The moisture content of the filter cake remains high.
Causes: Firstly, adjust the dosage of polyacrylamide during the sludge dewatering process. Secondly, select the most suitable polyacrylamide based on the characteristics of the iron ore wastewater, taking into account both molecular weight and degree of ionisation.