Basically, the limitation on the grinding capacity of iron ore mines is one of the challenges of increasing the capacity of pelletizing units along with the program of increasing steel production in our country. Therefore, the purpose of this research is to investigate the operational solution for obtaining appropriate quality of green pellets of fine concentrate with low specific surface area (less than 1500 cm2/g). Pilot pelletizing process was carried out by mixing fine concentrates of Chadermallo and Bafgh with blain number from 1220 to 1392 cm2/g and various additives such as bentonite, sodium carboxymethylcellulose (CMC), sodium hydroxide and sodium carbonate. Wettability of iron ore particles was evaluated with distilled water, process water, CMC solution and sodium hydroxide. The particle size analyzer and Fisher were used for determination of particle size distribution and specific surface area of concentrate powder, respectively. The drop number, wet strength and dry strength were measured for evaluation of the quality of green pellets produced. High wettability was measured when Carboxymethyl cellulose organic binder solution was used. To maintain the qualitative properties of green pellet, proportional to reduction of blain number of concentrate powder from 1396 to 1220 cm2/g and as well as avoid the increasing bentonite consumption, the CMC organic viscose solution has been added to the mixture of 0.01 to 0.03 %wt. the dry strength of the pellets to 5.5 kg/pellet was increased, by addition of sodium carbonate without of NaOH.

In Lines 5 and 6 of Gol Gohar Mineral and Industrial Complex the special surface of concentrate (Blain) is increased by the high pressure grinding rolls equipment (HPGR). At present, due to changes in the input feed of the plant, the magnetite concentrate moisture has increased. Increasing the moisture content of the material will reduce the HPGR operational gap, thereby reducing the feed rate and the effective pressure on the particles. As a result, Blain Concentrate will not be desirable. After checking of the process, it was determined that the parameters of vacuum pump pressure, filtration time, solid particle size and solid pulp percentage were effective on the filtering process. For this purpose, filtration experiments were carried out at different levels of each of the above parameters. In this research, four types of surfactants SDS, PEG, CTAB and SLES were used to study their effect on moisture reduction and filtration process. The results showed that the optimal conditions of the process parameters to achieve the minimum moisture content is 60 Kpa operating pressure, optimum dewatering time was 120 seconds, particle size 105 microns, proportional to the separation of Hydrocyclones and 60% solids content of pulp proportional to transfer equipment. Surfactant experiments showed that by adding 100 g/t anionic surfactant SDS to the pulp, the filter cake moisture content was reduced by 2%. The SDS increased filtration efficiency by decreasing the time of forming the filter cake and increasing the filtrate volume, especially at the time of forming the cake. The use of SDS improves filtration performance by increasing the ratio of throughput to moisture. At a concentration of 100 g/ton SDS and SLES, the lowest moisture of filter cake and the highest throughput was achieved. The ratio of throughput to moisture content for SDS was highest compared to other surfactants. SLES was selected with the same results as SDS at a concentration of 75 g/t, and because of its cost-effectiveness and availability, it was chosen as the final filter aid.

In the present work the possibility of utilization of remained mud of alumina extraction process from wastes of Zarand coal washing plant as an additive to cement was investigated. According to the chemical characteristics of mud, it was found that it is not possible to use the mud as cement raw materials. Therefore the main effort in this project was focused on the using the mud as an additive to the cement. Because of this the amounts of 2, 3, 5, 10, 15, 20, 25 and 30 wt% of mud were added to cement type 2 (as control sample).Parameters of alkali, L.O.I, free lime, and fineness of cement mixtures (blain) were measured, also cement mortar molds based on the ASTM C 109 were made. Primary and final setting ,compression strength and volume expansion of them after 2, 3, 7, 28 and 90 days were determined. It must be mentioned that in order to compare the results a mixture of 20wt% Pozzolan with 80wt% cement and control sample was made. The cement mortar resistance against diffusion of chloride was determined based on the ASTM C 1202 .

The SARS-COV-2 virus is the cause of the 2020 pandemic that has infected and killed millions worldwide. While the upper respiratory tract cells are the primary targets of COVID-19, the virus can infiltrate other tissues and organs, leading to potentially serious complications. The new coronavirus primarily affects angiotensin II receptor and cytokine pathways, which can result in acute pulmonary inflammation, pulmonary edema, acute respiratory distress syndrome, vascular endothelial dysfunction, pulmonary embolism in the lungs, and cardiomyopathy, arrhythmia, heart failure, and intravenous thrombosis in the heart. COVID-19 infection can be associated with gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain. Also, reports of mild and transient liver damage, polyneuropathy, encephalitis, stroke, acute renal failure, hypocortisolism, and damage to the hypothalamus and pituitary system are available. COVID-19 can also be associated with skin symptoms such as rash, urticaria, maculopapular lesions, and vascular lesions such as chill blain, petechiae purpura, and scalpopathy. This narrative review evaluates the pathogenesis of novel coronavirus on body organs based on relevant published papers and reference books.

This study investigates factors affecting the Blaine number, including type, shape, and size distribution of the grains, d80 effect, and retention time of materials in the mill. Samples were taken from different locations in production lines of the Golgohar and Chadormalu plants in Iran. For iron minerals, Davis tube tests were performed in four stages to assess the functionality of the magnetic separator to ensure matching conditions between the plant and laboratory. The Blaine air permeability system was used to analyze the Blain number. Results indicated that the samples with the same d80 but different grain size distributions had different Blaine numbers. More specifically, increasing the percentage of grains finer than 45 microns resulted in higher Blaine numbers. Moreover, in the Golgohar Hematite and desulfurization plant, the grain size distribution was relatively fixed, and minor variations in the percentages of grains finer than 45 microns led to a change in the Blaine number, and this was consistent between different days. During the concentrate production processes, higher grades of iron concentrate and lower grades of non-iron minerals were associated with lower Blaine numbers, which could be explained by the removal of iron-free minerals finer than 45 microns, including clay. Moreover, a 1% reduction in the clay minerals led to a 400-unit reduction in the Blaine number. Several samples of hematite concentrate and clay minerals with the same grain size distribution were analyzed to investigate the influence of density and the shape of grains on the Blaine number of magnetite concentrate. Here, compared to magnetite and hematite with irregular shapes, plate-shaped clay minerals showed higher Blaine numbers. Moreover, when the feed of the magnetic separator was grinded, the reduction in the grain size increased the Blaine number. In the Chadormalu plant, a retention time of 4.5 minutes in the mill was associated with the highest Blaine number as well as the least recovery of phosphorous minerals.

The primary raw material of the steel industry is iron. This paper aims to optimize magnetite recovery from wet tailings by increasing the iron content in the concentrate of the line. To manage tailings, a Wet Tailing Processing (WTP) line constructed at Gol-e-Gohar Iron Ore Company to recover the magnetite. The dominant crystalline phases in these tailings were quartz, albite, talc, hematite, and calcite. The line feed is 45 microns, which is not suitable for the gravity method. Thus, separation can achieve using only the magnetic method. Because of the high iron content in the tailings, a wet magnetic separator is used. According to the results, the proposed medium-intensity separator and the associated circuit modifications increase iron recovery from 7 to 30 percent; resulting in 150 tons of annual production; preventing loss of iron through concentrator plant tailings, and increasing the Blain number by 50 to 100 units in the hematite plant. Furthermore, water consumption is significantly reduced by replacing old wet tailings of the concentrator plant with new wet tailings as the feed, which is another significant achievement of this research. Instead of fresh water, saline water with flow rate of 250 cubic meters per hour are used.

In this research, natural pozzolanic materials were used in cement production to reduce the emission of CO2 and energy consumption. The rate of substitution of cement with natural pozzolan powder varied from 20% to 50% in 100 samples. Compressive strength tests were carried out on mortar specimens (4×4×16 cm3) after 2, 7, and 28 days. The obtained activity index was approximately 85% and volcanic ash was pozzolan. The compressive strength values changed from 122 to 318 kg/cm2 after 7 days and from 201 to 433 kg/cm2 after 28 days. However, the reduction of CO2 emission with 20% to 50% of additive amounted from 130.74 tons to 419.32 tons of CO2 per ton of clinker. By using 3 to 53% of additives, electricity consumption decreases from 1.89 to 33.39 kWh per ton of clinker. Moreover, this amount of additive can raise energy savings from 99160.8 to 1751841.8 kJ per ton of clinker.

Cement production is responsible for consuming 13% of energy along with producing 7% of CO2 worldwide. Using supplementary cementitious materials (SCMs) such as pozzolans could be helpful in this regards, while it could potentially improve the properties of concrete. The results of previous investigations have illustrated the fact that pozzolans partially replacing cement as binaries (one pozzolan along with cement), resulted in the improvement of concrete's durability parameters in many cases. On the other hand, one of the main uses of pozzolans is in self-consolidating concrete (SCC), a special concrete that has gain attention and popularity in recent years due to its specific properties. Recent studies on SCC containing ternary (two pozzolans along with cement) blends revealed impressive improvements in the mechanical and specially durability properties, outperforming both binaries and non-pozzolanic mixes. This was attributed to the fact that using pozzolans resulted in great decrease in permeability caused by their filler effect along with transformation of CH to CSH or CASH. Also their high blain causes significant improvement in the pore structure of concrete. In this context, capillary pores increase in number, each with much lower volume and diameter compared to non-pozzolanic samples. Another consequence of using these materials is less porosity of the interfacial transition zone (ITZ). Overall, the numerous beneficial effects of using pozzolans in concrete is well-established, and this could promote the use of more pozzolans in concrete.   Nevertheless, there has few investigations concerning the effects of ternary mixes on the durability of SCC, and studying the properties of quadratics mixes (three pozzolans along with cement) has been rarely done. On this basis, the purpose of this research was to study the effects of using binary, ternary and quadratic blends on durability characteristics of SCC. In this regards, two natural pozzolan, namely trass and pumice, were used as cement replacements at 0, 10 and 20% levels in mixes containing 10% silica fume. Various tests on the fresh properties of SCC including slump flow as flow ability and J ring as filling ability test were performed. As for hardened concrete, the 28 day compressive strength, velocity of ultrasonic pulses in concrete, water absorption, depth of penetration of water under pressure, Surface Resistivity toward Chloride Ion Penetration and rapid chloride penetration (RCPT) tests were considered.The results showed that binaries, only in compressive strength and to some extent in pulse velocity performed better compared to ternaries and quadratics. Also, it was concluded that ternaries slightly outperformed quadratics in terms of compressive strength, pulse velocity, and water penetration tests, whereas quadratics generally had slight superiority over ternaries in terms of electrical resistivity and rapid chloride penetration. Overall, choosing the best performance for each test result, using ternaries and quadratics decreased compressive strength, pulse velocity, water absorption, water penetration and rapid chloride penetration by 5%, 3%, 15%, 61%, 71% respectively, while increased electrical resistivity by 55% compared to binary mixture. In addition, all mixtures had desirable, water absorption below 2% and binaries, ternaries and quadratics had similar results with no significant differences.

More than 100,000 Iranian veterans and civilians still suffer from various long-term complications due to their exposure to sulfur mustard (SM) during the Iran–Iraq war in 1983–88. The aim of the study was to investigate DNA damage of SM in veterans who were exposed to SM, 23–27 years prior to this study. Blood samples were obtained from the veterans and healthy volunteers as negative controls. Lymphocytes were isolated from blood samples and DNA breaks were measured using single-cell microgel electrophoresis technique under alkaline conditions (comet assay). Single cells were analyzed with “Tri Tek Comet Score version 1.5” software and DNA break was measured based on the percentage of tail DNA alone, or in the presence of H2O2 (25 μM) as a positive control. A total of 25 SM exposed male veterans and 25 male healthy volunteers with similar ages (44.66 ± 6.2 and 42.12 ± 5.75 years, respectively) were studied. Percentage of the lymphocyte DNA damage was significantly (p < 0.01) higher in the SM-exposed individuals than in the controls (6.47 ± 0.52 and 1.31 ± 0.35, respectively). Percentages of DNA damage in the different age groups of 35–39, 40–44, 45–49, and 50–54 years in SM-exposed veterans (5.48 ± 0.17, 6.7 3 ± 1.58, 6.42 ± 0.22, and 7.27 ± 0.38, respectively) were all significantly (p < 0.05) higher than the controls (1.18 ± 0.25, 1.53 ± 0.22, 1.27 ± 0.20, and 1.42 ± 0.10, respectively). The lymphocytes incubated with H2O2 had much higher DNA damage as expected. The average of tail DNA is 42.12 ± 2.75% for control cells + H2O2 and 18.48 ± 2.14% for patients cells + H2O2; P < 0.001. SM exposure of the veterans revealed DNA damage as judged by the comet assay.

Occult Hepatitis B (OHB), or persistent hepatitis B virus (HBV) viremia in surface-antigen-HBsAg-negative patients, has been recognized as a medical concern during the last decade. The exact magnitude, pathogenesis and clinical relevance of OHB are unclear. This review organizes the published data on OHB and presents an overview of the current hypotheses on OHB’s pathogenesis and clinical relevance.Many explanations have been offered for the pathogenesis of OHB, ranging from the inability of standard immunoassays to diagnose OHB to the involvement of the versatile virus–host factorsAlso, special care should be taken regarding the diagnosis of OBH. It seems that both shared viral-host factors are involved in the pathogenesis of OBH. Further molecular studies on cohort patients group need to explore such association.