Red mud is an important solid tailing with strong alkalinity that is obtained during the extraction of alumina in the Bayer process. The global reserve of red mud is more than 4 billion tons, and its disposal as tailing has always been a serious environmental problem. This tailing is considered as a potential source, due to its high content of valuable metal compounds including iron. In this research work, the extraction of iron in red mud is investigated by the method of Reduction Roasting. The main influencing factors are also investigated. These methods include Reduction in muffle and tube furnace, and temperature, Reduction agent, and additive type are as important factors. Reduction Roasting of the samples in a tube furnace, with Argon gas and vacuum, a mixture of red mud, graphite, and sodium carbonate at 700–1000 °C results in the formation of Fe3O4. Magnetic measurements indicate that saturation magnetization increases from 0.239 to 38.205 emu/g due to the formation of Fe3O4. Applying the magnetic field intensity of about 1000 Gauss results in the iron recovery of 89.9%.

The Chehel-Kureh copper deposit in southeastern Iran contains complex sulfide ores rich in copper, lead, and zinc, posing significant challenges for conventional flotation processing. Despite various flotation strategies, the plant has struggled to produce clean copper concentrates and separate lead and zinc products, resulting in low recoveries and environmental concerns due to metal losses in tailings. In this study, the application of Waelz kiln technology—a process commonly used for zinc recovery from metallurgical residues—was investigated as an alternative approach for metal recovery from Chehel-Kureh ore. Reduction Roasting experiments were conducted on raw ore, as well as differential and bulk flotation concentrates, using coal as a reductant. The effects of Roasting temperature, duration, and coal ratio on metal volatilization were examined. Under optimal conditions, volatilization of lead, copper, and zinc reached 89%, 84%, and 75% for the raw ore; 92%, 62%, and 74% for the differential concentrate; and 68%, 62%, and 43% for the bulk concentrate, respectively. These findings indicate that the Waelz process can achieve high metal volatilization efficiencies, particularly for lead and zinc, offering a promising alternative for pre-treatment and recovery of valuable metals from complex Cu–Pb–Zn ores while potentially minimizing environmental impacts.

In this paper, the effect of infrared (IR) Roasting conditions on Aflatoxins and total counts of two types of Iranian pistachio kernels, long and round, was studied. The optimized Roasting conditions, 70 V for round pistachios and 90 V for long pistachios with 10 cm distance from IR source were used. Naturally Aflatoxin-contaminated kernels were supplied and roasted. Microbiological and Aflatoxins tests were done before and after Roasting, and the results were analyzed by t-test at 5% confidence level. It was shown that 64. 00% of total Aflatoxins and 63. 99% of Aflatoxin B1 were reduced in long roasted pistachio nut kernels after IR-Roasting. However, the Reduction levels were 71. 40% and 64. 94% for total Aflatoxins and Aflatoxin B1 in round pistachio kernels, respectively. Total counts Reduction was 99. 99% in the round and 99. 97% in the long pistachio kernels. In addition, mold and yeast numbers were reduced 99. 99% in the round and 99. 97% in the long pistachio kernels. Considering mild conditions (90°, C and 11. 5 min) in IR-Roasting process, considerable amounts of Reduction in bacteria, mold, and yeast, and the most important Reduction of Aflatoxins. This research has shown that IR-Roasting process can be considered as an effective method for pistachio nut Roasting in Aflatoxin contamination Reduction.

Roasted watermelon seeds are consumed as snack foods. In this research, the Response Surface Methodology (RSM) was used in order to examine the effect of Roasting on some physicochemical properties of watermelon seeds. The Central Composite Design (CCD) was applied to investigate the effects of two independent variables, i. e. temperature (180-260  C) and time (5-15 min), on moisture content, texture, color, total phenol, and antioxidant activity. According to the results, increasing the temperature and prolonging the duration of Roasting caused Reductions in the moisture content,  E and texture hardness. Meanwhile, the total phenol content and antioxidant activity increased. The linear, quadratic, and interactive effects between the independent variables (temperature and time) were significant on moisture content and texture hardness (p<0. 05). All variables, except the quadratic effect of time and the quadratic effect of the two independent variables, caused significant changes to the antioxidant activity and total phenol content. However, the total difference in color was only significantly affected by the linear effect of the two variables. Finally, Roasting conditions (i. e. Roasting temperature and time) were optimized in a manner that the acquired model-generated results akin to the experimental data (desirability=0. 74).