In this study, samples from Zefreh Dolomite mine were characterized by X-ray diffraction and microscopic study. Dolomite samples were heated up to 1700oC to produce doloma. Zircon and zirconia were used for preparation of Dolomite – zirconia refractories. Samples containing different contents of zirconia and zircon were heated up to 1600oC. Apparent porosity, bulk density, X-ray diffraction, cold compressive strength, hydration resistance tests and SEM studies were carried out on the fired samples. Results show that samples containing zirconia have higher quality than samples containing zircon without additives.

In this study, the production of magnesium oxide (MgO) from Dolomite ore (CaMg(CO₃) ₂) sourced from a mine in the southern region of the country was investigated.  Following sample collection, Dolomite was transported to the Iranian Mineral Processing Research Center for XRF, ICP, XRD, and TGA-DTA analyses. The results of mineralogical and chemical analyses indicated that Dolomite and calcite were predominant minerals, both critical for magnesium production. The calcination process at a particle size of 3 mm and a temperature of 800°C converted Dolomite into an oxide phase. Magnesium oxide was subsequently produced through acid leaching using 2M HCl at a solid-to-liquid ratio of 5:15 at 70°C for 3 hours. The precipitation process using NaOH at a pH of 8–9 resulted in the formation of magnesium hydroxide, which was further heated at 600°C to convert it into magnesium oxide (MgO).The results demonstrated that the complete production of magnesium oxide is feasible at the Iranian Mineral Processing Research Center. This study highlights the high potential of the Dolomite mine in the southern region as a source of raw material for MgO production and emphasizes the need to develop industrial infrastructure to complete the value chain of this strategic material.

Presence of heavy metals in water resources is a critical environmental challenge in various communities. To date, various methods have been applied to remove heavy metals, such as the use of cost-efficient materials. The present study aimed to evaluate the adsorption of heavy metals (iron, zinc, nickel, lead, and cadmium) on Dolomite and thermally-modified Dolomite. We assessed the potentials of natural and thermally-modified Dolomite in terms of the adsorption of heavy metals from aqueous solutions. The samples were analyzed to determine the concentrations of metal ions using Spectra 200 Varian. For the optimization and evaluation of the influential factors in the adsorption amount, factors such as the initial concentration of the solution, pH, contact time, and adsorbent dosage were considered. Comparison of the final removal results indicated that lead and cadmium had the shortest contact time (15 minutes), while the longest contact time belonged to iron and nickel (60 minutes). In addition, the highest and lowest removal efficiency within the optimum time was 99% and 93%for cadmium and iron, respectively, while the minimum dosage of the optimum adsorbent belonged to iron and zinc. The minimum removal efficiency belonged to nickel (3 mg/l), while the maximum removal efficiency was obtained for cadmium, iron, and zinc (10, 5, and 5 mg/l) with the concentrations of 99%. According to the results, modified Dolomite has great potential to remove metals and heavy metals. . .

In production of magnesium by vacuum silicothermic reduction of calcined Dolomite, Pidgeon process, experimental parameters such as temperature, time, density of briquettes and the ratio of stoichiometric requirement of silicon can be employed to control reduction efficiency and silicon efficiency. To model the effects of these parameters on reduction process, a basic statistical approach was utilized. Experimental data are inputs to the model. What about response of The model was compared with actual reduction data, in which temperature, time, density of briquettes and the ratio of stoichiometric requirement for reduction, were varied. A statistical "design of experiments" approach was undertaken in process experimentation and the optimium conditions of Pidgeon process were determined.

Shahmirzad village is located on the southern parts of the Eastern Alborz Mountain Ranges. One of the sedimentary rock units that crops out in this area is Soltanieh Formation (Upper Precambrian Lower Cambrian). Thin section and oxygen isotope studies have been used in order to determine the petrological characteristics and the temperature of Soltanieh Dolomites formation environment. Examination of the petrographic properties of the Dolomite samples, along with geochemical data reveals that all of the Dolomite samples are diagenetic (secondary) and were formed under reducing conditions in shallow to deep phreatic environment. The heaviest and lightest 180 values illustrate that temperature of early to late diagenetic Dolomites range from 72 oC to 113.5 oC respectively.

Thermal behavior of the Shahreza Dolomite ore is investigated in this paper. The hydration of the calcined Dolomite was studied as a function of the calcination temperature. The DTA results exhibit three endothermic peaks at 800, 900 and 1050˚C, corresponding to decomposition of MgCO3 and CaCO3, both are present in Dolomite and free calcite, respectively. The results also indicated that the degree of calcination is increased by increasing the calcination temperature from 800 to 1400 cc. As the calcining temperature increases from 800 to 900°C, the hydration degree of the dolime increases too because of more humid absorbing phases produced at higher temperature. However, the hydration degree declines with further increase in the calcination temperature and became negligible when the sample is calcined at 1400°Cprobably due to the sintering process occurred at elevated temperatures.

Dolomite refractories have a good production potential in Iran due to the existence of high-quality Dolomite ore in many regions of the country, particularly in Isfahan and Hamedan. The basic problem associated with the production and use of this type of refractories is inherent tendency to hydration of calcined Dolomite. One of the methods to overcome this problem is to increase the amount of magnesia in doloma. This study focuses on the use of Iranian Dolomite to produce magnesia -doloma (mag-dol) refractory with high resistance to hydration and corrosion. It was found that addition of 20wt% magnesite to Dolomite would result in capsulating of CaO by MgO that protects doloma from further hydration.

Different types of dolomitic carbonate rocks of Upper Cretaceous which are located in northeast of Shahmirzad, Centeral Alborz, hosted many lead-zinc deposits and occurrences. In this study 5 profiles of carbonate rocks of abandoned lead-zinc mines from Reza-Abad, Heydar-Abad and Reza-Barak have been selected. petrogenesis and composition of Dolomites have been studied employing equation N CaCO3 = md + b, using stained thin sections, XRD graphs, Wet chemical analysis and XRF. Dolomites of this region are categorized in to 3 groups due to amount of calcium carbonate in which ranges from 49.5-51.5%, 51.5-53.5% and 53.5-55.5%.respectively Considering a/m studies, six types of Dolomite textures have been recognized, which according to growth sequence of Dolomite crystals in time, are consist of: Xenotopic A, Idiotopic E, P, S, C and Saddle Dolomite. The decreasing of Na2+ and Sr2+ that create along diagenesis and increase crystal size, has not observed because of the influence of hydrothermal fluids on Cretaceous sequences. The amount of Fe2+ and Mn2+ are higher in dolosparite in comparison with dolomicrosparite. Considering the changes the amount of Fe2+, Mn2+ and Sr2+ in the composition of Dolomites along profiles, it may be that there had been a flowing fluid from north to the south in accordance to Anzab Fault. Taking in to consideration the data gathered in the studies, the several-stage dolomitization in the region should be related to the early and late stage diagenesis. This may be due to sea and meteoric waters, basin waters, saline waters and influence of hydrothermal fluids. This phenomena occure during Cenozoic that may be associated with Eocene volcanic activities, which was affected to the Upper Cretaceous sequences.

Background: Pityriasis rubra pilaris (PRP) is a rare skin disease characterized by follicular hyperkeratosis and prefollicular erythema with islands of normal skin scattered among erythematous patches with desquamation.Case Report: In this case report, we present a 30-year-old man who developed pityriasis rubra pilaris (PRP) following exposure to Dolomite.Conclusion: The diagnosis of PRP was confirmed histologically and the patient was successfully treated with acitretin and cyclosporine.