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  • Author: Krzysztof Mazurek x
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Extraction of vanadium and potassium compounds from the spent vanadium catalyst from the metallurgical plant

A spent vanadium catalyst, from the plant of metallurgical type, was leached in a sulfuric acid solution to recover vanadium and potassium compounds. The effect of time, temperature, concentration of acid, catalyst particle size and phase ratio was studied. Additionally the concentration of iron, copper, zinc, arsenic and lead compounds was determined. The flow sheet for the proposed process of spent vanadium catalyst leaching is presented.

Abstract

The effect of time, temperature, the catalyst particle size and the ratio of the catalyst weight to the leaching solution volume (S:L) on the treatment of spent vanadium catalyst components was determined using citric acid solutions at atmospheric pressure. The optimal parameters of catalyst leaching in 10% acid solutions at atmospheric pressure are: T = 323 K, t = 4 h, the particle size of less than 0.160 mm, the S:L ratio below 0.1. Under these conditions it was possible to dissolve about 90% of vanadium and potassium compounds and more than 60% of iron compounds contained in the catalyst. These results fall within the scope of research on a comprehensive method for recovering spent vanadium catalyst components.

Plotting of the solubility isotherm for the NH4NO3 + NaVO3 + H2O system

The equilibrium research was performed for the NH4NO3 + NaVO3 + NH4VO3 + NaNO3 + H2O system at 293 and 303 K. The location of the P1 and P2 triple points was determined on the equilibrium plots with the planar projection according to Jänecke method. The maximum yield of the conversion of ammonium nitrate(V) to ammonium vanadate(V) was calculated at P1 points. The results constitute the basis to design further equilibrium experiments aimed to precisely determine the lines separating the areas of the co-crystallization of salts in the investigated system on the equilibrium plots in the oblique projection on a plane according to Jänecke method.

Extraction of vanadium compounds from the used vanadium catalyst with the potassium hydroxide solution

The paper presents the results of the research on the degree of the recovery of vanadium(V) from the used vanadium catalyst with the use of KOH solution. The extraction was performed at 293 - 323 K, for 0.5 to 4 h and the catalysts of the variable grain diameter. The concentration of the extracting solution was varied in the range 5 - 20%. The optimal ratio of solid to liquid phase S/L was determined. Additionally the degree of the recovery of total iron ions was presented.

Abstract

The paper presents the concept of installation of an electricity generator and en energy store inside a roller of belt or roller conveyor. Accordingly, the use of a generator-pulley does not require any structural changes to be made to an existing conveyor. In addition, the user will be able to power distributed sensors network for monitoring the operation of the belt conveyor anywhere on its route.

Abstract

A spent vanadium catalyst, from the plant of metallurgical type, was leached in a potassium hydroxide solution to recover vanadium. The effect of time, temperature, concentration of basic, catalyst particle size and phase ratio was studied. The results showed that for a 160-750 μm catalyst leached for 4 h at 313.15 K in the presence of 10% potassium hydroxide solution at a liquid: solid ratio of 20:1, the extent of leaching of V was about 87%. Additionally, separation of vanadium from such a solution was investigated by the ion exchange method. Two types of polymer strongly basic ion exchangers were used. The ion exchange tests indicate that vanadium were loaded from the post-leaching solution with high effi ciency. On this basis a fl owsheet for the proposed process of a complex utilization of the spent vanadium catalyst is presented.

Summary

Study aim: the aim of study was assessment somatic features and selected cardio-ventilatory indices in men above 50 years old with different physical activity levels.

Materials and methods: the study included 55 men on average aged 54.5 ± 4.32, classified to the trained group (T), n = 33, and not trained group (NT), n = 22. Total physical activity was assessed using the SDPAR Questionnaire. Measurements: anthropometric indices, ventilatory indices and VO2 peak, hemodynamic indices and fatigue using Borg scale during exercise maximal test.

Results: daily energy expenditures for sport and recreation differ significantly between T and NT groups, 6.82 METs vs. 0.2 METs, respectively (p < 0.001). Men in T and NT groups significantly differ in somatic features, and cardio-pulmonary indices including: time of physical tests effort (s) 1103 ± 193 vs. 681 ± 328; max speed (km/h) 14 ± 1.5 vs. 10 ± 1.4, VE peak 135.9 ± 21.17 l/min vs. 112.9 ± 21.49 l/min; VO2 peak 61.8 ± 8.83 ml/kg/min vs. 41.9 ± 8.55 ml/kg/min; HR rest (beat/min) 69 ± 16.95 vs. 83 ± 14.48; HR peak (beat/min) 171 ± 1.23 vs. 163 ± 15.28; SV peak (ml) 162 ± 24.23 vs. 135 ± 33.22; CO peak 27.4 ± 4,3 vs. 21.6 ± 5.17.

Conclusions: men aged 50+ who practice running training differ favourably and significantly from men not trained in anthropometric as well as cardio-ventilatory indices. Significant correlations were found between DEE and FAT(%), VO2 peak (ml/kg/min), SV peak (ml) and COpeak (l/min) as well between CO peak and VO2peak was record linear relationship (r = 0.56).

The index of insulin resistance (FIRI) is not associated with plasma homocysteine levels in young, non-obese healthy men and women

Study aim: To evaluate plasma homocysteine (Hcy), insulin and glucose levels in blood and the insulin resistance index (FIRI) in young, healthy non-obese men and women.

Material and methods: A total of 152 young, healthy, non-obese (BMI<30) men (n = 81) and women (n = 71) participated in the study. The following substances were assayed in blood using commercial kits: total plasma homocysteine by fluorescence polarisation immunoassay, plasma glucose - by the oxidase method, and insulin by radioimmunoassay using monoclonal antibodies. From the latter two, the index of insulin resistance (FIRI) was computed.

Results: Mean plasma homocysteine concentration in men was significantly (p<0.001) higher than in women (10.3 ± 3.0 and 8.4 ± 2.4 μmol/l, respectively) and that of FIRI was significantly (p<0.001) lower than in women (1.310 ± 0.483 and 1.437 ± 0.420, respectively). Neither in men nor in women were plasma homocysteine concentrations correlated with FIRI.

Conclusions: Although no association between circulating homocysteine and FIRI was found in young, non-obese men and women, the existence of such association in Type 2 diabetes cannot be ruled out.

Anthropometric and cardio-respiratory indices and aerobic capacity of male and female students

Study aim: To assess the relations between anthropometric and cardio-respiratory indices, and aerobic capacity of students, differing in the level of physical activity, under resting and exercise conditions.

Material and methods: A group of 87 male and 75 female students volunteered to participate in the study. Their physical activity was evaluated by Seven-Day Physical Activity Recall questionnaire. Anthropometric (body height and mass, body fat content, BMI and WHR) and physiological indices (heart rate, blood pressure, O2max, CO2 and minute ventilation) were recorded. Body fat content was determined using a BIA device; respiratory data were recorded in a cycle ergometer test. The subjects were classified by their O2max values into ‘high’ or ‘low’ categories, the cut-off values of lower and upper quartiles serving as criteria.

Results: Male and female students expended 10.2 ± 4.6 and 8.4 ± 5.3 kcal/kg/day, respectively, the O2max amounting to 48.4 ± 6.4 and 41.1 ± 4.7 ml/kg/min, respectively. Subjects having high O2max had significantly higher energy expenditure on physical activities, fat-free mass, body water content and maximal ventilation, and lower body mass, BMI, body fat content, resting heart rate and diastolic pressure.

Conclusions: When investigating into the relationships between physical activity and physiological features, the latter ought to be related to O2max rather than to energy expenditure which may depend on other than physiological variables.

Abstract

Quality of life (QOL) is associated with factors such as health, physical functioning, life satisfaction, a sense of happiness, and others. In case of disabled people, much attention is paid to their QOL rather than only the improvement of physiological variables. In a group of blind and visually impaired people, the effect of physical activity (PA) on the socialization process, the ability to explore own personality traits, developing creativity, and more motivation and desire to overcome the difficulties associated with visual impairment were observed.

The study involved 53 people: visually impaired (NT) sedentary lifestyle people (n=18; 51±12 years) and visually impaired tandem cycling athletes (N) (n=17; 42±13 years). Properly sighted people (P) (n=18; 38±12 years) were partners in tandem with visually impaired athletes. To determine the level of PA, the International Physical Activity Questionnaire (IPAQ) was used. The WHO-Quality of Life (WHO-QOL-BREF), the National Eye Institute 25-item Visual Functioning Questionnaire (NEI VFQ-25, version 2000), and the Retina AMD Poland Association questionnaire were used to assess QOL.

In visually impaired athletes, significantly greater PA with moderate intensity, moving by bike, and energy expenditure for vigorous recreational exercise and sport in leisuretime was found. Sedentary lifestyle people mainly participated in moderate physical activity around the house. Significant greater satisfaction with health was observed in the case of visually impaired athletes in comparison with NT. All disabled groups rarely had negative feelings such as despair, depression, and anxiety.

Moderate correlations between variables according to physical activity and quality of life in all participants were observed. The meaningfulness of life and life satisfaction also depended on cycling training and moderate physical activity around the house. The obtained data indicate that all available forms of regular PA in visually impaired people could have a beneficial effect on their quality of life.