Musa Sarikaya

Flotation characteristics of oxidized coal

Abstract The floatability of oxidized coal was investigated by means of electrokinetic studies, contact angle measurements and flotation tests. Electrokinetic measurements showed that the zeta potential of unoxidized and oxidized coal samples depends on pH. Hydroxonium and hydroxyl ions are potentially significant ions, both for oxidized and unoxidized coal. Increasing oxidation times decreased the measured iso-electric points and increased the negative zeta potential. In the presence of cationic collectors the negative value of the zeta potential for oxidized coal was changed to a positive value below pH 9.3–10.9 depending on the type and concentration of collector used. Contact angle measurements indicated that the natural flotability of unoxidized coal was found to deteriorate on oxidation. Addition of cationic collectors increased the value of the contact angle of oxidized coal. Flotation tests showed that as the degree of oxidation increases, the floatability of coal decreases. Cationic collectors were found to be effective in the flotation of oxidized coal.

Comparison of non-ionic and ionic collectors in the flotation of coal fines

Some ionic collectors were used as an alternative to conventional non-ionic collectors to obtain clean concentrates from fine coal samples containing 46.1% ash. Mixtures of kerosene and pine oil were used as conventional reagents while commercial fatty acids were used as ionic collectors. Flotation results showed that conventional collectors could not reduce the ash content of concentrate below 21.0% whereas, ionic collectors were found significantly better at reducing the ash content down to 16%, but their yields were lower.

Some Aspects of Magnetic Filtration Theory for Removal of Fine Particles from Aqueous Suspensions

The magnetic filtration theory was evaluated to intensify the filtration of industrial fluids by magnetic filters. Effects of filtration velocity and external magnetic field intensity on filter performance were investigated and the dependence of the logarithmic efficiency coefficient on filtration velocity was questioned. It was concluded that change in the magnetic susceptibility of the dispersion particles, caused by external magnetic field, and change in the flow rate properties of the liquid alongside the filter pores are the most essential factors to be considered in the design, development, and modeling of magnetic filtration systems in various industrial areas.

The effect of grinding on pyrophyllite flotation

The effects of dry grinding on flotation recovery of pyrophyllite were investigated using an alcohol type frother. Before and after dry grinding for several periods, pyrophyllite was examined using DTA-TG, XRD, FTIR analyses and flotation tests. It was concluded that dry grinding for longer times affects the flotation recovery of pyrophyllite, since the crystal structure is distorted by mechanical treatment.

Leaching of Celestite with Sodium Sulfide

Leaching of celestite mineral, SrSO4, with sodium sulfide, Na2S, was investigated from the point of strontium carbonate, SrCO3, production. Experiments were carried out to explain the conversion mechanism of celestite to strontium disulfide, SrS2, in Na2S solution. Effects of stirring speed, particle size, and concentration of Na2S on conversion were studied at constant temperature and solid‐to‐liquid ratio. The results showed that the rate of conversion mainly depends on Na2S concentration. It was concluded that leaching of celestite in Na2S solution for conversion to SrS2 is possible but slow.

Utilization of Fine Coal Tailings by Flotation Using Ionic Reagents

Fatty acid type ionic collectors were used as an alternative to conventional oily collectors, kerosene, and pine oil mixture in the flotation of coal tailing with 46.1% ash. The conventional collectors could not reduce the ash content of the concentrate below 22%. On the other hand, ionic collectors were found to be significantly better at reducing the ash content down to 13%. It was concluded that despite their lower flotation yield and higher consumptions, certain ionic collectors could be used successfully in coal flotation where cleaner concentrates are required from coal fines with high ash content.

Influence of Microwave Heating and Thermal Auxiliary on Decomposition of Siderite

In the present study, microwave radiation was used to decrease power inputs and roasting duration time for thermal decomposition of Deveci, Hekimhan siderite ore. The siderite was not enough to absorb adequate microwave radiation to start the decomposition or roasting reaction. Therefore, sucrose as a thermal auxiliary was added to the raw siderite ore before microwave irradiation. The effect of amount of sucrose (10 to 30% by weight) against the duration of heating and roasting temperature of the thermal decomposition of siderite was investigated in the present study. On the contrary of the literature, the experimental results showed that the siderite was decomposed in 3 minutes with addition of 30 wt% sucrose and transformed to Fe3O4. The temperature, the weight loss and the magnetic susceptibility of the roasted final product were recorded as 1100 °C, 32.14 wt.% and 15410.03*10-8 m3/kg., respectively.

Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

Production of Nano Amorphous SiO2 from Malatya Pyrophyllite

Pyrophyllite (Al4Si8O20(OH)4) is an important industrial clay mineral. In this paper, highly pure nano silica powder was synthesized by alkaline treatment method from the local pyrophyllite deposit which is in Malatya, Turkey. The morphologies, structures and properties of the raw pyrophyllite and the obtained nano amorphous SiO2 were determined by XRF, XRD, ATR, SEM and EDX. The results showed that the nano silica can be produced with a high purity (98%) and nano size (< 50 nm).

Computational Chemistry Approach to Interpret the Crystal Violet Adsorption on Golbasi Lignite Activated Carbon

In this paper, adsorption mechanism of Crystal Violet (CV) dye from the aqueous solution on the activated carbon prepared from Golbasi lignite was explained and interpreted by a computational chemistry approach and experimental studies. Molecular dynamic simulations and Ab initio frontier orbital analysis indicated relatively high energy and electron transfer processes during adsorption, and molecular dynamics simulations showed CV dye molecules moving around on the activated carbon surface after adsorption, facilitating penetration into cracks and pores. The experimental results supported to molecular dynamic simulation and showed that the monolayer coverage occurred on the activated carbon surface and each CV dye ion had equal sorption activation energy.