scholarly journals Insights into Selection of the Auxiliary Collector and Its Applicability Analysis for Improving Molybdenite Flotation

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Hui Li ◽  
Tingshu He ◽  
He Wan ◽  
Yuexin Han ◽  
Yufeng Guo ◽  
...  
Keyword(s):  
Low Temperature ◽  
Negative Impact ◽  
Subsequent Treatment ◽  
Mass Ratio ◽  
Practical Application ◽  
Flotation Concentrate ◽  
Percentage Points ◽  
Polycyclic Aromatic ◽  
Methyl Naphthalene ◽  
Selection Of

In this study, two auxiliary collectors (methyl naphthalene and naphthalene) of molybdenite and the traditional collector (kerosene) were mixed for molybdenite flotation, respectively. According to the selection and analysis of the auxiliary collector, it was found that the surface energy (γC= 4.50 mJ/m2) of the polycyclic aromatic hydrocarbons is very close to that (γS= 42.55 mJ/m2) of the molybdenite {100} surface. Therefore, it can be physically adsorbed onto the molybdenite {100} surface according to the principle of similar compatibility. Batch flotation was conducted on actual ore with the mixed collector, compared with kerosene alone. Batch flotation results showed that the mixed collector at a mass ratio of 95:5 of main collector to auxiliary collector at pH 11.0 improved molybdenite flotation, that is, the Mo recovery was increased by 3–4%. The practical application feasibility of the auxiliary collector was analyzed by the filtration speed of the flotation concentrate and the crystal resolution characteristics of the auxiliary collector. The results show that solid naphthalene (Nap) is easy to crystallize at low temperature and adhere to the surface of the flotation concentrate, resulting in a decrease of filtration velocity, while liquid methylnaphthalene (MNap) does not crystallize at low temperature. These results imply that the mixed collector Kerosene/MNap can generate a superior synergistic effect and achieve better collecting capacity than kerosene alone, resulting in the increase of flotation recovery by 3–4 percentage points. Moreover, the addition of MNap has little negative impact on the subsequent treatment of the product.

Commissioning brownstock washing controls for an evaporator limited mill

TAPPI Journal ◽  
2016 ◽  
Vol 15 (7) ◽  
pp. 459-464
Author(s):  
RICARDO SANTOS ◽  
PETER HART
Keyword(s):  
Control System ◽  
Negative Impact ◽  
Black Liquor ◽  
Pulp Mill ◽  
Control Program ◽  
Separation Point ◽  
Water Control ◽  
Oxygen Delignification ◽  
Percentage Points

An automated shower water control system has been implemented to reduce the volume and variability of weak black liquor being sent from the pulp mill to the evaporators. The washing controls attempt to balance the need for consistent and low soda carryover to the bleach plant with consistently high weak black liquor solids being sent to the evaporators. The washer controls were implemented on two bleachable grade hardwood lines (one with oxygen delignification, one without oxygen delignification) and one pine line. Implementation of the control program resulted in an increase in black liquor solids of 0.6 percentage points for the hardwood lines. Significant foam reduction was realized on the pine line since the pine black liquor solids were able to be consistently maintained just below the soap separation point. Low black liquor solids excursions to the evaporators were eliminated. Bleach plant carryover was stabilized and no negative impact on chemical consumption was noticed when controlling weak black liquor solids to recovery.

THE CONCEPT, TYPES, TASKS AND THE NEED FOR THE USE OF URGENT INVESTMENT TOOLS OF CRISIS MANAGEMENT AT ENTERPRISES

2017 ◽  
Author(s):  
Oksana Yurynets ◽  
Keyword(s):  
Crisis Management ◽  
Economic Condition ◽  
Negative Impact ◽  
Negative Influence ◽  
Management Program ◽  
Management Tools ◽  
The Subject ◽  
Effective Development ◽  
Selection Of

Currently, many Ukrainian enterprises are in crisis. Getting out of this situation requires the use of various types of urgent crisis management tools, among which investment instruments play an important role. The purpose of this article is to form the theoretical basis for the use of urgent investment tools of crisis management at enterprises. It was found that the urgent investment tools of crisis management in the enterprise should be understood as ways of immediate (urgent) investment actions which are aimed at eliminating or reducing the negative impact of the crisis on the economic condition of the enterprise and ensuring its further effective development. These instruments are grouped according to the following characteristics: the environment in which the relevant instruments are formed and operate, the relation to the current owners of the enterprise, the effectiveness of implementation, the duration of the effect of implementing instruments, the urgency of their implementation, the areas of investment, the objectives of application, the duration of application, the types of financial and economic crises at the enterprise, the elimination (reduction) of the negative influence of which the corresponding tools are directed at, the subject of investment. It is established that the main tasks of using investment urgent tools of anti-crisis management at the enterprises are: selection of the best types of investment urgent tools of anti-crisis management; selection of the best variant of each type of urgent investment tools of crisis management; setting deadlines for the implementation of selected types and options for urgent tools of crisis management at the enterprise; determination of the optimal amount of total investments that should be invested in the implementation of the crisis management program at the enterprise, and the corresponding to this volume of the general list of investment urgent tools of such management; identifying the best sources of investment and establishing the best structure of investment in terms of these sources.

CRITERIA FOR SELECTION OF PREPARATIONS IN THE DEVELOPMENT OF SORPTION-DETOXIFYING COMPLEXES FOR AGRICULTURAL ANIMALS

2018 ◽  
Vol 1 (2) ◽  
pp. 94-100
Author(s):  
L.L. Zakharova ◽  
◽  
G.A. Zhorov ◽  
V.I. Dorozhkin ◽  
◽  
...  
Keyword(s):  
Chemical Nature ◽  
Negative Impact ◽  
Physiological State ◽  
Animal Husbandry ◽  
Biologically Active ◽  
Combined Pollution ◽  
Wide Range ◽  
Active Substances ◽  
Criteria For Selection ◽  
Selection Of

Negative impact on the environment as a result of economic activity of man increasingly becomes the character of combined pollution of ecotoxicants, including xenobiotics of radiation and chemical nature. In animal husbandry in ecologically unfavorable regions, sorbtion-detoxication technologies based on the complex application of bioprotective substances of different origin are used to reduce the intake and accumulation of xenobiotics, to normalize the physiological state of animals and to obtain safe products. It is necessary to observe certain principles ensuring compatibility of components, a wide range of bioprotective action, efficiency and safety at their use in developing the compositions of such sorption-detoxifying complexes. The article substantiates the criteria that should be followed in creating sorption-detoxifying complexes and presents groups of drugs with different mechanisms of action (sorbents, antioxidants, immunomodulators, adaptogens and other biologically active substances) for inclusion in the formulations of combined compositions.

scholarly journals FUZZY MULTI-CRITERIA DECISION MAKING MODEL FOR SUBCONTRACTOR SELECTION IN INTERNATIONAL CONSTRUCTION PROJECTS

2015 ◽  
Vol 22 (2) ◽  
pp. 210-234 ◽  
Author(s):  
Serdar ULUBEYLI ◽  
Aynur KAZAZ
Keyword(s):  
Construction Projects ◽  
Decision Criterion ◽  
Practical Application ◽  
Human Judgment ◽  
Qualitative And Quantitative ◽  
International Construction ◽  
Weak Points ◽  
Initial Idea ◽  
Decision Making Model ◽  
Selection Of

A general contractor’s ability to select proper subcontractors in foreign projects is a key competitive advantage. Toward this aim, a subcontractor selection model (CoSMo) was developed in this study. As a computational approach, the fuzzy sets method was employed because it can model human judgment by means of linguistic values, combining qualitative and quantitative decision criteria into an aggregate measure. Although the algorithm may be complex for easy acceptance by industrial practitioners, this disadvantage was minimized through a computer-supported system. In order to gain a better understanding of the current practice of CoSMo, a real world construction project was conducted. As a result, it was observed that CoSMo has high practical application and can be used as an advisory system by satisfying principal contractor’s requirements to reduce the risk involved in the selection of a subcontractor. Moreover, it gives an initial idea of how subcontractors perform on each decision criterion and allows the main contractor to understand the picture on the strong and weak points of each bidder and thereby to take conscious decisions.

scholarly journals Three Evidence Based Methods to Compensate for a Lack of Subject Background when Ordering Chemistry Monographs

2008 ◽  
Vol 3 (3) ◽  
pp. 3
Author(s):  
Robert A. Wright
Keyword(s):  
Statistical Analysis ◽  
Statistical Significance ◽  
Evidence Base ◽  
Circulation Rate ◽  
Evidence Based ◽  
Practical Application ◽  
Present Evidence ◽  
Library System ◽  
Over Time ◽  
Selection Of

Objective – The aim of this article is to present evidence based methods for the selection of chemistry monographs, particularly for librarians lacking a background in chemistry. These methods will be described in detail, their practical application illustrated, and their efficacy tested by analyzing circulation data. Methods – Two hundred and ninety-five chemistry monographs were selected between 2005 and 2007 using rigorously-applied evidence based methods involving the Library's integrated library system (ILS), Google, and SciFinder Scholar. The average circulation rate of this group of monographs was compared to the average circulation rate of 254 chemistry monographs selected between 2002 and 2004 when the methods were not used or were in an incomplete state of development. Results – Circulations/month were on average 9% greater in the cohort of monographs selected with the rigorously-applied evidence based methods. Further statistical analysis, however, finds that this result can not be attributed to the different application of these methods. Conclusion – The methods discussed in this article appear to provide an evidence base for the selection of chemistry monographs, but their application does not change circulation rates in a statistically significant way. Further research is needed to determine if this lack of statistical significance is real or a product of the organic development and application of these methods over time, making definitive comparisons difficult.

Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study

2016 ◽  
Vol 74 (3) ◽  
pp. 580-585
Author(s):  
Masoumeh Golshan ◽  
Maryam Dastoorpour ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Time Course ◽  
Inoculum Size ◽  
Biosurfactant Production ◽  
Practical Application ◽  
Time Intervals ◽  
Initial Inoculum ◽  
Bacterial Inoculum ◽  
Polycyclic Aromatic ◽  
The Mean ◽  
Time Course Study

Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m−1 at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L−1 on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L−1, at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.

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