A Copper Oxide Ore Treatment by Flotation

2013 ◽  
Vol 813 ◽  
pp. 230-233
Author(s):  
Bao Liang Ge ◽  
Yan Xiong Fu ◽  
Qing Li
Keyword(s):  
Copper Oxide ◽  
Flow Sheet ◽  
Butyl Xanthate ◽  
Copper Oxidation ◽  
Two Stage ◽  
Main Metal ◽  
Pine Oil ◽  
One Stage ◽  
Ore Treatment ◽  
Oxidation Ratio

The ore containing 0.77%copper, the main metal minerals in the ore are hemesite, pyrite bornite, covellite, malachite, the main gangue minerals in the ore are quartzite, dolomite, plagioclase, Chlorite, calcite. And the copper oxidation ratio of the ore is 45.5%, According several flotation tests, finally found that the optimum reagents dosage are: butyl xanthate 90g/t as collector, pine oil 35g/t as foaming, sodium sulphide1000g/t, lime3000g/t, and the flow-sheet is one stage of roughing, three stage of cleaning and two stage of scavenging operationg in the close circuit under the grinding fineness is 85% -0.074mm.Satisfactory results had been obtained as the grade of is 18.06% with recovery 80.01%.

Research on Flotation Tests of Sulfide Copper Ore from Yunan

2013 ◽  
Vol 634-638 ◽  
pp. 3466-3471 ◽  
Author(s):  
Yi Jie Wang ◽  
Shu Ming Wen ◽  
Jian Liu ◽  
Qi Cheng Feng ◽  
Meng Yang Lv
Keyword(s):  
Mineral Processing ◽  
Copper Recovery ◽  
Closed Circuit ◽  
Iron Deposit ◽  
Flow Sheet ◽  
Optimum Conditions ◽  
Butyl Xanthate ◽  
Copper Ore ◽  
One Stage ◽  
Concentrate Grade

The mineral processing flow sheet and reagent system of flotation copper minerals from a large copper-iron deposit in Yunnan were fully investigated. The results indicate that the optimum conditions for flotation of copper minerals from the material were identified as grinding fineness of 85%, dosage of CaO at 2000g/t , dosage of Na2S at 200 g/t, dosage of butyl xanthate 40g/t. Under such a condition, a copper recovery of 88.17% with a concentrate grade of 26.86% was achieved from the material using a closed circuit flow sheet of "one-stage roughing flotation, one-stage cleaning flotation and one-stage scavenging flotation.

Investigation on Copper Flotation from a Complex Copper Ore, Yunnan Province

2015 ◽  
Vol 1094 ◽  
pp. 389-392 ◽  
Author(s):  
Chuan Fa Cui ◽  
Yong Jun Xian ◽  
Shu Ming Wen ◽  
Yi Jie Wang
Keyword(s):  
Yunnan Province ◽  
Copper Recovery ◽  
Sulfide Deposit ◽  
Flow Sheet ◽  
Optimum Conditions ◽  
Butyl Xanthate ◽  
Two Stage ◽  
Copper Ore ◽  
Concentrate Grade ◽  
Complex Copper

The mineral processing flow sheet and reagent system of flotation copper minerals from alarge copper sulfide deposit in Yunnan were fully investigated. The results indicated that the optimum conditions for flotation of copper minerals from the material were identified as follows: grinding fineness of 80%(-0.074mm), dosage of CaO 800g/t, butyl xanthate 100g/t.Under such condition, a copper recovery of 90.57% with a concentrate grade of 19.52% was achieved from the material using a closed circuit flow sheet of one-stage roughing flotation, two-stage cleaning flotation and two-stage scavenging flotation.

Molecular genetic background of haemophilia A patients with discrepancy between one-stage and two-stage factor VIII assays

2010 ◽  
Vol 30 (S 01) ◽  
pp. S153-S155
Author(s):  
D. Delev ◽  
S. Pahl ◽  
J. Driesen ◽  
H. Brondke ◽  
J. Oldenburg ◽  
...  
Keyword(s):  
Factor Viii ◽  
Genetic Background ◽  
Molecular Genetic ◽  
Haemophilia A ◽  
Two Stage ◽  
One Stage

Plasma Factor V Activation Is Prevented by Activated Protein C in the Presence of Phospholipid Vesicles, Not Platelets

1993 ◽  
Vol 69 (02) ◽  
pp. 124-129 ◽  
Author(s):  
Susan Solymoss ◽  
Kim Thi Phu Nguyen
Keyword(s):  
Western Blotting ◽  
Protein C ◽  
Thrombin Generation ◽  
Blood Platelets ◽  
Activated Protein C ◽  
Phospholipid Vesicles ◽  
Factor V ◽  
Two Stage ◽  
One Stage ◽  
Plasma Factor

SummaryActivated protein C (APC) is a vitamin K dependent anticoagulant which catalyzes the inactivation of factor Va and VIIIa, in a reaction modulated by phospholipid membrane surface, or blood platelets. APC prevents thrombin generation at a much lower concentration when added to recalcified plasma and phospholipid vesicles, than recalcified plasma and platelets. This observation was attributed to a platelet associated APC inhibitor. We have performed serial thrombin, factor V one stage and two stage assays and Western blotting of dilute recalcified plasma containing either phospholipid vesicles or platelets and APC. More thrombin was formed at a given APC concentration with platelets than phospholipid. One stage factor V values increased to higher levels with platelets and APC than phospholipid and APC. Two stage factor V values decreased substantially with platelets and 5 nM APC but remained unchanged with phospholipid and 5 nM APC. Western blotting of plasma factor V confirmed factor V activation in the presence of platelets and APC, but lack of factor V activation with phospholipid and APC. Inclusion of platelets or platelet membrane with phospholipid enhanced rather than inhibited APC catalyzed plasma factor V inactivation. Platelet activation further enhanced factor V activation and inactivation at any given APC concentration.Plasma thrombin generation in the presence of platelets and APC is related to ongoing factor V activation. No inhibition of APC inactivation of FVa occurs in the presence of platelets.

Two-Stage Procedure for the Quantitative Determination of Autoprothrombin III Concentration and Some Applications

1967 ◽  
Vol 18 (01/02) ◽  
pp. 198-210 ◽  
Author(s):  
Ronald S Reno ◽  
Walter H Seegers
Keyword(s):  
Prothrombin Time ◽  
Factor Vii ◽  
Two Stage ◽  
Pronounced Increase ◽  
One Stage ◽  
Assay Procedure ◽  
Bovine Plasma ◽  
The One ◽  
Autoprothrombin C

SummaryA two-stage assay procedure was developed for the determination of the autoprothrombin C titre which can be developed from prothrombin or autoprothrombin III containing solutions. The proenzyme is activated by Russell’s viper venom and the autoprothrombin C activity that appears is measured by its ability to shorten the partial thromboplastin time of bovine plasma.Using the assay, the autoprothrombin C titre was determined in the plasma of several species, as well as the percentage of it remaining in the serum from blood clotted in glass test tubes. Much autoprothrombin III remains in human serum. With sufficient thromboplastin it was completely utilized. Plasma from selected patients with coagulation disorders was assayed and only Stuart plasma was abnormal. In so-called factor VII, IX, and P.T.A. deficiency the autoprothrombin C titre and thrombin titre that could be developed was normal. In one case (prethrombin irregularity) practically no thrombin titre developed but the amount of autoprothrombin C which generated was in the normal range.Dogs were treated with Dicumarol and the autoprothrombin C titre that could be developed from their plasmas decreased until only traces could be detected. This coincided with a lowering of the thrombin titre that could be developed and a prolongation of the one-stage prothrombin time. While the Dicumarol was acting, the dogs were given an infusion of purified bovine prothrombin and the levels of autoprothrombin C, thrombin and one-stage prothrombin time were followed for several hours. The tests became normal immediately after the infusion and then went back to preinfusion levels over a period of 24 hrs.In other dogs the effect of Dicumarol was reversed by giving vitamin K1 intravenously. The effect of the vitamin was noticed as early as 20 min after administration.In response to vitamin K the most pronounced increase was with that portion of the prothrombin molecule which yields thrombin. The proportion of that protein with respect to the precursor of autoprothrombin C increased during the first hour and then started to go down and after 3 hrs was equal to the proportion normally found in plasma.

Standardization of Factor VIII – IV. Establishment of the 3rd International Standard for Factor VIII: C Concentrate

1983 ◽  
Vol 50 (03) ◽  
pp. 697-702 ◽  
Author(s):  
T W Barrowcliffe ◽  
A D Curtis ◽  
D P Thomas
Keyword(s):  
Factor Viii ◽  
High Purity ◽  
Collaborative Study ◽  
World Health ◽  
Current Standard ◽  
Two Stage ◽  
International Standard ◽  
One Stage ◽  
The One ◽  
Health Organization

SummaryAn international collaborative study was carried out to establish a replacement for the current (2nd) international standard for Factor VIII: C, concentrate. Twenty-six laboratories took part, of which 17 performed one-stage assays, three performed two-stage assays and six used both methods. The proposed new standard, an intermediate purity concentrate, was assayed against the current standard, against a high-purity concentrate and against an International Reference Plasma, coded 80/511, previously calibrated against fresh normal plasma.Assays of the proposed new standard against the current standard gave a mean potency of 3.89 iu/ampoule, with good agreement between laboratories and between one-stage and two- stage assays. There was also no difference between assay methods in the comparison of high-purity and intermediate purity concentrates. In the comparison of the proposed standard with the plasma reference preparation, the overall mean potency was 4.03 iu/ampoule, but there were substantial differences between laboratories, and the two-stage method gave significantly higher results than the one stage method. Of the technical variables in the one-stage method, only the activation time with one reagent appeared to have any influence on the results of this comparison of concentrate against plasma.Accelerated degradation studies showed that the proposed standard is very stable. With the agreement of the participants, the material, in ampoules coded 80/556, has been established by the World Health Organization as the 3rd International Standard for Factor VIII :C, Concentrate, with an assigned potency of 3.9 iu/ampoule.

scholarly journals Comparing the use of aggregate data and various methods of integrating individual patient data to network meta-analysis and its application to first-line ART

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Steve Kanters ◽  
Mohammad Ehsanul Karim ◽  
Kristian Thorlund ◽  
Aslam H. Anis ◽  
Michael Zoratti ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Evidence Base ◽  
Aggregate Data ◽  
World Health ◽  
Coefficient Estimates ◽  
Two Stage ◽  
Individual Patient Level ◽  
One Stage ◽  
Meta Regression ◽  
Empirical Priors

Abstract Background The 2018 World Health Organization HIV guidelines were based on the results of a network meta-analysis (NMA) of published trials. This study employed individual patient-level data (IPD) and aggregate data (AgD) and meta-regression methods to assess the evidence supporting the WHO recommendations and whether they needed any refinements. Methods Access to IPD from three trials was granted through ClinicalStudyDataRequest.com (CSDR). Seven modelling approaches were applied and compared: 1) Unadjusted AgD network meta-analysis (NMA) – the original analysis; 2) AgD-NMA with meta-regression; 3) Two-stage IPD-AgD NMA; 4) Unadjusted one-stage IPD-AgD NMA; 5) One-stage IPD-AgD NMA with meta-regression (one-stage approach); 6) Two-stage IPD-AgD NMA with empirical-priors (empirical-priors approach); 7) Hierarchical meta-regression IPD-AgD NMA (HMR approach). The first two were the models used previously. Models were compared with respect to effect estimates, changes in the effect estimates, coefficient estimates, DIC and model fit, rankings and between-study heterogeneity. Results IPD were available for 2160 patients, representing 6.5% of the evidence base and 3 of 24 edges. The aspect of the model affected by the choice of modeling appeared to differ across outcomes. HMR consistently generated larger intervals, often with credible intervals (CrI) containing the null value. Discontinuations due to adverse events and viral suppression at 96 weeks were the only two outcomes for which the unadjusted AgD NMA would not be selected. For the first, the selected model shifted the principal comparison of interest from an odds ratio of 0.28 (95% CrI: 10.17, 0.44) to 0.37 (95% CrI: 0.23, 0.58). Throughout all outcomes, the regression estimates differed substantially between AgD and IPD methods, with the latter being more often larger in magnitude and statistically significant. Conclusions Overall, the use of IPD often impacted the coefficient estimates, but not sufficiently as to necessitate altering the final recommendations of the 2018 WHO Guidelines. Future work should examine the features of a network where adjustments will have an impact, such as how much IPD is required in a given size of network.

Sign in / Sign up

Export Citation Format

Share Document