Determining the Separation Performance of the Knelson Concentrator

This study was aimed at determining the separation performance of the Knelson concentrator in Zonguldak fine coal (-1+0.15 mm). The experiments were carried out in the Knelson concentrator under the following optimal parameters determined in previous studies; water flow rate of 3.14 L/min., bowl speed of 459 rpm, solids ratio of 23.87%, and feed flow rate of 1.50 L/min. A series of tests were conducted at optimal test parameters to obtain enough samples for float and sink analysis. Clean coal and tailing products were subjected to float and sink analysis. Based on this analysis, partition curve for coal cleaning process was generated. The cut-point of the separation was obtained at the specific gravity of 1.72 [g/cm3]. The probable error (Ep) value, which signifies the efficiency of the process, was calculated as 0.11 These results indicated that Knelson concentrator is very effective in separating fine coal.

Characterization and Beneficiation Options for Tungsten Recovery from Yxsjöberg Historical Ore Tailings

Repositories of historical tungsten mining tailings pose environmental risks, but are also potential resources for valuable metals. They still contain large tonnages of useful minerals and metals, reflecting the inefficient extraction methods and/or low metal prices at the time they were mined. The focus of this study is to evaluate the technical viability of reprocessing the tailings to recover some of the contained valuable minerals and metals, as well as reducing the negative environmental impact associated with the tailings. Geometallurgical studies were conducted on drill core samples taken from the Smaltjärnen tailings repository of the closed Yxsjöberg tungsten mine, Sweden. The collected samples were characterized physically, chemically, and mineralogically. Knelson concentrator dry low- and high-intensity magnetic separation methods were tested as potential beneficiation methods. The tailings are dominated by the −600 to +149 µm particles. The highest concentration of tungsten (W) was 0.22% WO3. Using a Knelson concentrator, scheelite (main W mineral) recovery was enhanced, with 75 wt.% tungsten recovered in the 34 wt.% heavy concentrate. Only 1.0 wt.% sulphur (S) reported to the non-magnetic fraction. Based on the findings, a methodology and a preliminary process flowsheet for reprocessing the tailings is proposed.

Investigation and Comparison of the Enrichment Potential of Turkey (Şenkaya, Erzurum) Coals with Knelson Concentrator

The quality of coals from, Erzurum varies widely. Two coal samples from this area were compared. The first has a composition of 19% ash, 5700 kcal, and 3% sulfur while the other has 49.20% ash, 3000 kcal, and 1.6% sulfur composition. It is understood that the first coal sample is a high-quality coal. Although the ash content of the second coal sample is determined to be high and the calorie value is low, the low sulfur content is advantageous for the environment. This study aimed at increasing the quality of coal samples by carrying out experiments for reducing the ratio of ash and sulfur with Knelson’s enrichment processes. Chemical analysis, sieve analysis experiments, %ash, %moisture, and %calorie values of each fraction are determined from two different C1 and C2 coal samples taken from the Balkaya village belonging to Şenkaya, Erzurum. Then, %ash, %yield, and %sulfur analyzes were carried out on the coal samples using the Knelson gravity separator enrichment method, and the results were evaluated for coal samples.