Study on low-grade galena-barite ore beneficiation in Khuzdar, Balochistan, Pakistan

Purpose. Galena and barite are the principal minerals of lead and barium respectively. Both minerals are used extensively in industries because of their distinct properties. In complex poly metallic ores, it is always desirable to produce separate mineral concentrates for subsequent metal extraction. Separation of two or more minerals from complex low-grade multi-metallic ore into commercial grade concentrates requires suitable process. Methods. This research work is centered on development a suitable process for the beneficiation of a low-grade galena-barite ore originating from Khuzdar region (Balochistan Province, Pakistan). Findings. The low-grade ore assaying 39.90% Pb and 24.64% BaSO4 was beneficiated on bench-scale by sequential froth flotation process to recover valuable galena and barite concentrates. The important variables of froth flotation process such as feed size, pulp pH, pulp density, impeller speed, type and quantities of flotation reagents, pulp conditioning time and froth collecting time were optimized to achieve maximum recovery and grade of both concentrates. The rougher galena and barite concentrates were re-ground separately and subjected to one cleaning flotation to obtain better grade final concentrates of respective minerals. Originality. A process flow-sheet was designed in the light of this study. Practical implications. Froth flotation experiments showed that a galena concentrate containing 77.38% Pb with recovery of 90.64% and a barite concentrate assaying 90.23% BaSO4 with recovery of 80.16% could be recovered from this ore. Both the concentrates fall in the category of metallurgical and chemical grades and are suitable for industrial applications.Мета. Підвищення якості низькосортної галеніт-баритової руди, знайденої в Хуздарском районі провінції Белуджистан (Пакистан), до концентрату металургійного якості, що містить більше 70% Pb, із використанням методу пінної флотації. Методика. Масова проба галеніт-баритової руди вагою близько 100 кг була відібрана з шахти Мал-Хор на північному заході від Хуздару та доставлена в лабораторію переробки мінералів MPRC, PCSIR Lahore для проведення досліджень. Зразок підданий первинному подрібненню із використанням щокової дробарки з наступним вторинним подрібненням із використанням валкової дробарки. Зразок до і після флотації піддавався комплексному хімічному і рентгеноструктурному аналізу (XRD). Флотаційні випробування проводилися на лабораторній флотаційній машині D-12. Після визначення оптимального помелу були проведені випробування для оптимізації щільності пульпи, рН пульпи, швидкості перемішування, кількості доданих реагентів, часу флотації й часу кондиціонування. Результати. Встановлено, що вміст свинцю та барію в поліметалічній руді є достатнім для промислового використання. Отримано оптимальну ступінь подрібнення і відновлення при розмірі подачі 80% мінус 200 меш. Виявлено, що збільшення щільності пульпи дещо знижується при збільшенні В/Т з 20 до 35%, але відновлення збільшується, а максимальне відновлення досягнуто при 30%. При використанні для коригування рН пульпи етілксантата калію, а потім бариту з олеатом натрію, виявлено, що при постійних умовах розміру часток і співвідношення твердої речовини та рідини максимально повторне покриття галену досягається при рН 8.5 і бариту при рН 10.0. Було відзначено, що невелика зміна pH значно змінила ступінь і відновлення. Розкрито вплив швидкості перемішування робочого колеса й відзначено, що оптимальною швидкістю на грубій стадії є швидкість 1100 об/хв, а на стадії очищення – 1000 об/хв. Доведено, що методом пінної флотації з даної руди можна отримати концентрат галеніту із вмістом 77.38% Pb і ступенем відновлення 90.64%, а також концентрат бариту із вмістом 90.23% BaSO4 і ступенем відновлення 80.16%. Наукова новизна. Встановлено характер впливу специфічних речовин, що поліпшують показники про-процесу флотації, які сприяють якісному відділенню цінних компонентів руди від порожніх домішок. Практична значимість. Розроблено принципову схему процесу збагачення галеніт-баритової руди на основі пінної флотації в замкнутому циклі. Отримані концентрати галеніту й бариту відповідають необхідним металургійним і хімічним стандартам та можуть знайти промислове застосування.Цель. Повышение качества низкосортной галенит-баритовой руды, найденной в Хуздарском районе провинции Белуджистан (Пакистан), до концентрата металлургического качества, содержащего более 70% Pb, с использованием метода пенной флотации. Методика. Массовая проба галенит-баритовой руды весом около 100 кг была отобрана из шахты Мал-Хор к северо-западу от Хуздара и доставлена в лабораторию переработки минералов MPRC, PCSIR Lahore для проведения исследований. Образец подвергнут первичному дроблению с использованием щековой дробилки, с последующим вторичным дроблением с использованием валковой дробилки. Образец до и после флотации подвергался комплексному химическому и рентгеноструктурному анализу (XRD). Флотационные испытания проводились на лабораторной флотационной машине D-12. После определения оптимального помола были проведены испытания для оптимизации плотности пульпы, рН пульпы, скорости перемешивания, количества добавленных реагентов, времени флотации и времени кондиционирования. Результаты. Установлено, что содержание свинца и бария в полиметаллической руде является достаточным для промышленного использования. Получена оптимальная степень измельчения и восстановления при размере подачи 80% минус 200 меш. Выявлено, что увеличение плотности пульпы несколько снижается при увеличении В/Т с 20 до 35%, но восстановление увеличилось, а максимальное восстановление достигнуто при 30%. При использовании для корректировки рН пульпы этилксантата калия, а затем барита с олеатом натрия, обнаружено, что при постоянных условиях размера частиц и соотношения твердого вещества и жидкости максимальное повторное покрытие галена достигается при рН 8.5 и барита при рН 10.0. Было отмечено, что небольшое изменение pH значительно изменило степень и восстановление. Раскрыто влияние скорости перемешивания рабочего колеса и отмечено, что оптимальной скоростью на грубой стадии является скорость 1100 об/мин, а на стадии очистки – 1000 об/мин. Доказано, что методом пенной флотации из данной руды можно получить концентрат галенита с содержанием 77.38% Pb и степенью восстановления 90.64%, а также концентрат барита с содержанием 90.23% BaSO4 и степенью восстановления 80.16%. Научная новизна. Установлен характер влияния специфических веществ, улучшающих показатели процесса флотации, что способствовало качественному отделению ценных компонентов руды от пустых примесей. Практическая значимость. Разработана принципиальная схема процесса обогащения галенит-баритовой руды на основе пенной флотации в замкнутом цикле. Полученные концентраты галенита и барита соответствуют металлургическим и химическим стандартам и могут найти промышленное применение.The authors are grateful to Associate Professor, Dr. Zulifqar Ali, Department of Mining Engineering, University of Engineering and Technology (UET), Lahore for his valuable support/ cooperation in X-ray diffraction (XRD) analysis and mineralogical evaluation of ore

Minority entrepreneurs’ exposure and journey in business: the underpinning assumptions and actions

YesIn this paper we introduce Morgan’s (1986, 1997) eight metaphors for making sense of entrepreneurs’ motives and their view of ‘reality’. Employing Burrell and Morgan’s (1979, 2003) four paradigms for the analysis of organisational theory, we propose a methodology to capture the ‘longitudinal’ journey of minority ethnic entrepreneurs’ original motives for setting up business; and, current and future perceived image. We use a deductive approach by developing a multiple-choice questionnaire based on eight metaphors. The data is collected from 30 small business owner managers/entrepreneurs based in Bradford, West Yorkshire. Our initial findings show that the assumptions of most of the respondents conform to the “functionalist” paradigm that place emphases on order, objectivity, rationality and tangible view of ‘reality’. Accordingly most of the respondents selected the functionalist metaphors like ‘Brain’, ‘Machine’ and ‘Psychic Prison’. Interestingly, most of the respondents selected and re-selected functionalist paradigm to indicate their past and future aspirations, perhaps due to their need for business stability and to subside any insecurity feelings with regards to their future. However, interestingly many respondents selected “radical Humanist” or “interpretivist” paradigms to map their current situation. These paradigms portray relatively more entrepreneurial and explorative mindset, perhaps mimicking unease with the current situation and a desire by the respondents to introduce some kind of a change in their current business and social settings. We believe that their metaphorical assumptions could determine their decision making, policy and strategy setting, and, actions. In our view our research instrument is appropriate for conducting ‘longitudinal’ studies for eliciting past, current and future assumptions of entrepreneurs

Heuristic-based programable controller for efficient energy management under renewable energy sources and energy storage system in smart grid

An operative and versatile household energy management system is proposed to develop and implement demand response (DR) projects. These are under the hybrid generation of the energy storage system (ESS), photovoltaic (PV), and electric vehicles (EVs) in the smart grid (SG). Existing household energy management systems cannot offer its users a choice to ensure user comfort (UC) and not provide a sustainable solution in terms of reduced carbon emission. To tackle these problems, this research work proposes a heuristic-based programmable energy management controller (HPEMC) to manage the energy consumption in residential buildings to minimize electricity bills, reduce carbon emissions, maximize UC and reduce the peak-to-average ratio (PAR). We used our proposed hybrid genetic particle swarm optimization (HGPO) algorithm and existing algorithms like a genetic algorithm (GA), binary particle swarm optimization algorithm (BPSO), ant colony optimization (ACO), wind-driven optimization algorithm (WDO), bacterial foraging algorithm (BFA) to schedule smart appliances optimally to attain our desired objectives. In the proposed model, consumers use solar panels to produce their energy from microgrids. We also perform MATLAB simulations to validate our proposed HGPO-HPEMC (HHPEMC), and results confirm the efficiency and productivity of our proposed HPEMC based strategy. The proposed algorithm reduced the electricity cost by 25.55%, PAR by 36.98%, and carbon emission by 24.02% as compared to the case of without scheduling

Experimental and Process Modelling Investigation of the Hydrogen Generation from Formic Acid Decomposition Using a Pd/Zn Catalyst

The use of hydrogen as a renewable fuel has attracted great attention in recent years. The decomposition of formic acid under mild conditions was investigated using a 2%Pd6Zn4 catalyst in a batch reactor. The results showed that the conversion of formic acid increases with reaction temperature and with the formic acid concentration. A process-simulation model was developed to predict the decomposition of formic acid using 2%Pd6Zn4 in a batch reactor. The model demonstrated very good validation with the experimental work. Further comparisons between the 2%Pd6Zn4 catalyst and a commercial Pd/C catalyst were carried out. It was found that the 2%Pd6Zn4 demonstrated significantly higher conversions when compared with the commercial catalyst

The concept of district health management in Malaysia

Background: In Malaysia, public health services sector are administered by the Ministry of Health through its central headquarters to the state and district offices. The District Health Offices particularly manage and coordinate the delivery of an effective, efficient and affordable health services in the districts throughout Malaysia. Materials and Methods: The information and statistics used in this article are based on the data collected from reports, articles, and publications by the Ministry of Health Malaysia and journals published pertaining to the District Health Management in Malaysia. Result: A District Health Office is entrusted with two major roles; to deliver public health services and to manage resources within a district. Led by a Public Health Physician, it acts as a body to oversee the execution of the national health policies and strategies at the ground level and serves to enforce existing health related legislation. It is also responsible in disease monitoring and surveillance and also the achievement of specific health indicators for each activity. There are six major services provided by the District Health Office, namely the Family Health, Disease Control, Occupational Health, Food Quality Control, Health Education, as well as Environmental Health and Water Supply Services. Conclusion: A District Health Office functions as the basic operational level in Malaysia healthcare system. Being the backbone in government healthcare system, it is essential to provide a well organised and integrated health service in delivering quality healthcare services to the population

Experimental and process modelling investigation of the hydrogen generation from formic acid decomposition using a pd/zn catalyst

The use of hydrogen as a renewable fuel has attracted great attention in recent years. The decomposition of formic acid under mild conditions was investigated using a 2%Pd6Zn4 catalyst in a batch reactor. The results showed that the conversion of formic acid increases with reaction temperature and with the formic acid concentration. A process-simulation model was developed to predict the decomposition of formic acid using 2%Pd6Zn4 in a batch reactor. The model demonstrated very good validation with the experimental work. Further comparisons between the 2%Pd6Zn4 catalyst and a commercial Pd/C catalyst were carried out. It was found that the 2%Pd6Zn4 demonstrated significantly higher conversions when compared with the commercial catalyst

Seed priming enhances early growth and improves area of soil exploration by roots

Introduction: Seed priming has been conducted for centuries with growth advantages reported for a variety of different crops. Previous work has suggested priming does not offer a yield advantage despite an increased early growth if grown under ideal conditions. However, how these advantages unfold in regards to early root development is largely unknown.Results: We observed accelerated germination speed in primed seeds regardless of applied seed enhancement technology i.e. coating or pelleting. Additionally, we found significant differences in lateral root development in primed seeds vs non-primed seeds. Furthermore, we recorded an increase in volume and surface of embryo and perisperm indicating a distinct morphological change during the germination process of primed seeds compared to non-primed seeds.Conclusions: We attribute the enhanced early plant development in primed seeds to increased root development and thus enhanced volume of the soil resource mined for nutrients. This improvement can be detected four days after emergence within the root system throughout the early plant development despite an early transition from seed reserves to soil based growth. The understanding of below ground root architecture characteristics can improve the selection of appropriate seed enhancement technologies and seedbed management practices

Phenotypic Variations of Drought Tolerance Parameters in Maize (Zea mays L.) under Water Stress at Vegetative and Reproductive Stages

Two field experiments were conducted at Shambat and Medani in Sudan under water stress in vegetative and reproductive growth stages during the season (2003/2004). The objective of the study was to assess phenotypic variability and phenotypic correlation between drought tolerance parameters in maize genotypes. A split-plot layout within randomized complete block design with three replications was used for the experiment. Fifteen genotypes of maize were examined through the study. The effect due to genotypes x location was highly significant for all drought tolerance parameters studied. Highly significant and favorable correlation for Yw with SSI2, SSI3, GMP2, GMP3, STI2 and STI3, while highly significant and negative with Yd2/Yw and Yd3/Yw. Based on the result's drought stress at vegetative and reproductive stages of maize results in a drastic reduction in grain yield, and the strong positive correlation of Yw with SSI, GMP and STI, indicates that selection for high values of these parameters improves yield under stress and non-stress environments. Drought tolerance parameters can be used for improving grain yield and facilitate further efforts in maize breeding programs. Keywords: Correlation, drought, genetic variability, heritability, Maize (Zea mays L.).

Comparative Efficiency of Soil and Foliar Applied Zinc in Improving Yield and Yield Components of Wheat (Triticum aestivum L.) Variety Kiran-95

A field study was undertaken to evaluate the comparative efficacy of zinc application through soil and foliar spray on growth and yield of wheat variety Kiran-95 at Soil Chemistry Section, Agriculture Research Institute, Tandojam during Rabi 2013-14. The experiment was laid out in three replicated randomized complete block design. The treatments comprised Control (No Zinc), Soil applied Zinc 5.0 kg ha-1 at tillering stage, Soil applied Zinc 10.0 kg ha-1 at tillering stage, Soil applied Zinc 5.0 kg ha-1 at tillering + 5.0 kg ha-1 at booting stage, Foliar applied Zinc 0.2% at tillering stage, Foliar applied Zinc 0.4% at tillering and Foliar applied Zinc 0.2% at tillering stage + 0.2% at booting stage. The statistical analysis of data suggested that soil and foliar applied zinc affected significantly (P<0.05) growth and yield traits of wheat variety Kiran-95. The results illustrated that Soil applied Zinc 5.0 kg ha-1 at tillering + 5.0 kg ha-1 at booting stage produced maximum plant height (99.0 cm), tillers (410.7 m-2), spike length (13.1 cm), spikelets per spike (23.0), grains per  spike (45.1), seed index (43.4 g), biological yield (9354.4 kg ha-1) and grain yield (5123.4 kg ha-1), closely followed by Foliar applied Zinc 0.2% at tillering stage + 0.2% at booting stage with 97.6 cm plant height, 408.8 tillers m-2, 13.0 cm spike length, 22.8 spikelets per spike, 45.0 grains per spike, 43.2 g seed index, 9273.4 kg ha-1 biological yield and 5080.7 kg ha-1 grain yield. The performance of wheat variety Kiran-95 ranked 3rd, 4th, 5th and 6th almost in all the growth and yield parameters particularly grain yield (kg ha-1) when fertilized with Soil applied Zinc 10.0 kg ha-1 at tillering stage, Foliar applied Zinc 0.4% at tillering, Soil applied Zinc 5.0 kg ha-1 at tillering stage and Foliar applied Zinc 0.2% at tillering stage.  However, minimum growth and yield traits were registered in Control (No Zinc). Furthermore, the results concluded that although numerically maximum growth and yield values were recorded in Soil applied Zinc 5.0 kg ha-1 at tillering + 5.0 kg ha-1 at booting stage but statistically the differences between Soil applied Zinc 5.0 kg ha-1 at tillering + 5.0 kg ha-1 at booting stage and Foliar applied Zinc 0.2% at tillering stage + 0.2% at booting stage were non-significant. Hence, Foliar applied Zinc 0.2% at tillering stage + 0.2% at booting stage were found the most economical treatment for obtaining optimum yield of wheat variety Kiran-95. Keywords: Wheat, Comparative Efficiency, Soil, Foliar, Zinc, Improving Yield and Yield Component