Pyrite as a Low-Cost Additive in Sulfur Cathode Material for Stable Cycle Performance

Various materials have been reported as an efficient host for sulfur to suppress large volume variation and polysulfide shuttle in lithium-sulfur batteries. Carbon materials are widely used as a matrix for sulfur to improve cycle performance and confine sulfur. Addition of transition metal sulfides into cathode material can improve cycle stability due to high efficiency of chemisorption and suppressing the polysulfide diffusion. In this work, various additions of pyrite to carbon and sulfur in the cathode material were investigated. The results show that the amount of pyrite has an affect on capacity and cycle stability of the electrode. Consequently, the lithium-sulfur batteries with the composite cathodes, containing 10 % of pyrite, exhibits stable discharge capacity of 788 mAh g-1 after 60 cycles at 0.2 C. Pyrite is a promising electrocatalyst in advanced lithium-sulfur batteries in the merits of low-cost, eco-friendliness and high activity towards polysulfides conversion reaction.

Effect of Adding Sulfur and Organic Fertilizer on Growth and Yield of Onions (Allium Cepa L.) Under Different Plant Densities

A field experiment was conducted in the Amiriyat al-Fallujah district of the Anbar governorate to know the effect of the combination of sulfur and organic fertilizer on the growth and yield of onion, (a local red type), under different plant densities. The experiment included two factors, first: a combination of fertilizing with decomposing Cow’s manure (20 tons.ha-1) and sulfur (50 kg.ha-1), and this factor was distributed as follows (T0: fertilizer recommendation (NPK 100-100-120 kg.ha-1 It is considered a control). T1: cow waste + half of the chemical fertilizer recommendation and T2: fertilizer recommendation + sulfur addition and T3: Cow’s manure + half of the fertilizer recommendation + sulfur addition and T4: double the recommendation of cow manure (40 t.ha-1 + half of the fertilizer recommendation + adding sulfur). The second factor: planting distances (S1:10×10, S2:10×15, and S3:10×20) cm. The distance between plants was fixed 10 cm and the dimensions changed between one line and another. The study was carried out as a factorial experiment with the randomized complete block design (RCBD). The results showed clear significant differences for the two study factors in characteristics of vegetative growth, yield, and the content of total soluble solids, as the T4S3 treatment exceeded by giving it the highest number of tubular blades, leaf area and the highest percentage of sulfur in the leaves, which was positively reflected on the plant yield and percentage the total soluble solids amounted to (16.57 blades.plant-1, 15.97 dm2, 1.70%, 0.64%, 104.50 g, 15.83%), respectively, The treatment of planting distances S1 achieved significant differences in the total yield (90.39 tons.ha-1 and 8.91 kg) respectively compared to plants of treatment S3, which achieved(74.29 tons.ha-1and 5.39 kg).

The influence of sulfur addition on the hazard-type reaction of ilmenite ores with sulfuric acid

The paper presents results of thermokinetic investigation of the hazard-type reaction of Norwegian and Australian ilmenite ores with sulfuric acid, modified by the addition of elemental sulfur, to increase the process safety in industrial conditions. In the reactions of both ilmenite ores the addition of sulfur caused a reduction of the thermal power generated in the reaction and a decrease in the value of the thermokinetic parameter ΔTmax/Δτ for almost the whole range of initial concentrations of sulfuric acid. It was also found that the addition of sulfur to the reaction did not negatively affect the degree of ilmenite leaching. The interpretation of the obtained thermokinetic curves allowed to determine safe process conditions for both types of titanium raw materials.

Modelling and optimization of sulfur addition during 70MnVS4 steelmaking: An industrial case study

Štore Steel Ltd. is one of the major flat spring steel producers in Europe. Among several hundred steel grades, 70MnVS4 steel is also produced. In the paper optimization of steelmaking of 70MnVS4 steel is presented. 70MnVS4 is a high-strength microalloyed steel which is used for forging of connecting rods in the automotive industry. During 70MnVS4 ladle treatment, the sulfur addition in the melt should be conducted only once. For several reasons the sulfur is repeatedly added and therefore threatening clogging during continuous casting and as such influencing surface defects occurrence and steel cleanliness. Accordingly, the additional sulfur addition was predicted using linear regression and genetic programming. Following parameters were collected within the period from January 2018 to December 2018 (78 consequently cast batches): sulfur and carbon cored wire addition after chemical analysis after tapping, carbon, manganese and sulfur content after tapping, time between chemical analysis after tapping and starting of the casting, ferromanganese and ferrosilicon addition and additional sulfur cored wire addition. Based on modelling results it was found out that the ferromanganese is the most influential parameter. Accordingly, 12 consequently cast batches (from February 2019 to October 2019) were produced with as lower as possible addition of ferromanganese. The additional sulfur addition in all 12 cases was not needed. Also, the melt processing time, surface quality of rolled material and sulfur cored wire consumption did not change statistically significantly after reduction of ferromanganese addition. The steel cleanliness was statistically significantly better.

Technologically Sustainable Route for Metals Valorization from Jarosite-PbAg Sludge

By-products from zinc hydrometallurgy are classified as hazardous waste with strong leaching toxicities. Even though numerous research papers are dedicated to valorizing valuable metals in it, the primary management route is still disposal or partial reuse, such as the Waelz process. Presented experimental research investigates possibilities of sulfidization and further processing as a technologically sustainable route for valuable metals valorization from non-standard jarosite-PbAg sludge. The comprehensive thermodynamic analysis was done by HSC Chemistry®, through optimizing process parameters, i.e., temperature, sulfur addition, and selection of possible additives. Technological possibility of magnetic separation, flotation, and smelting of sulfidized material was also investigated; the results were below the values that allow practical application, due to the obtained texture of sulfidized jarosite, which does not allow the liberation of minerals. Smelting tests were performed on sulfidized jarosite with sulfur and without and with carbon as additive. By smelting sulfidized jarosite-PbAg sludge with added carbon in sulfidization stage at 1375 °C, obtained products were matte, slag, raw lead, and dust in which base, critical, and slag forming components were valorized. Valuable metals were concentrated in smelting products so as to enable further processing, which also could be interesting in the case of treatment of complex, polymetallic, and refractory primary materials, which represent a significant contribution to the circular economy.

Sulfur-Modified Composites for Enhancement of Building Foundations

This paper considers the issues of improving the strength characteristics of foundations by injecting specially selected composite mortars into soils. The properties of injection mortars used in seismic hazardous areas are improved using various additives consisting of various wastes. The article explores the possibility of using a composite mortar modified with sulfur, which is waste from oil refining. The influence of its addition on the strength characteristics of composite materials is studied. The optimal content of sulfur addition was determined, which makes it possible to increase the strength of building mixtures by 20-30%. The possibility to use a sulfur- modified composite mortar to strengthen an artificial foundation for reducing the seismicity of the construction site was proven.

The Effect of Amending Soil with Waste Elemental Sulfur on the Availability of Selected Macroelements and Heavy Metals

Elemental sulfur of waste origin may be a valuable sulfur source for plants. However, assessing the suitability of environmental use of a waste material should confirm there is no harmful effect of the material on soil environment. The purpose of the incubation experiment was to assess the availability of selected elements (P, K, Ca, Mg, Fe, Mn, Zn, Cu, Cr, Ni, Pb, Cd) in soils supplemented with waste elemental sulfur. The research was conducted on two soils: light and heavy, and with three sulfur doses applied to each soil. Available forms of elements in the soils were extracted 60 days after the waste introduction, with three reagents: 0.01 mol L−1 CaCl2, Mehlich 3 and 1 mol L−1 HCl. Additionally, to determine the impact of the introduced sulfur on soil acidification, soil pH was periodically checked during the experiment. The sulfur addition intensified acidification of the light soil, and, to a lesser extent, of the heavy soil. The acidifying effect was stronger when the sulfur dose was higher. The content of available forms of elements in the soils depended mainly on the strength of the used extractants (generally, the highest amounts were extracted with 1 mol L−1 HCl and the lowest with 0.01 mol L−1 CaCl2). The effect of sulfur introduction on element availability was small. No harmful effect on element availability in soils was stated.