Maximum Recovery Rate Research Articles

The effect of multiple lesions in patients with ossification of the posterior longitudinal ligament of the cervical spine

PurposeOssification of the posterior longitudinal ligament of the cervical spine (cervical OPLL) is associated with the lesions at the thoracic and/or lumbar spine. Multiple spinal lesions cause additional neurological deficit, affecting the outcomes of cervical laminoplasty. This study aimed to clarify the effect of multiple lesions on the outcomes of cervical laminoplasty and to compare the results with data from patients without them. MethodsFrom April 1981 to October 2015, 201 patients underwent laminoplasty for cervical OPLL; however, 167 patients were followed for >2 years. Twenty-four patients underwent additional surgery for multiple lesions due to spinal stenosis. The pathologies of the lesions were assessed. The patients were divided into two groups: the thoracic and thoraco-lumbar group (T-group: 8 patients) and the lumbar group (L-group: 16 patients). One-hundred patients without an additional surgery served as the control group. The maximum Japanese Orthopaedic Association (JOA) score and the most recent score for recovery was compared between the multiple and control groups. ResultsThe maximum score and recovery rate and the score and recovery rate at the last follow-up in the multiple group were lower than those in the control group. There was no significant difference in the postoperative JOA score and recovery rate between the T-group and the L-group. ConclusionsNeurological recovery in patients with multiple lesions was poorer than in those without lesions. Therefore, special attention should be paid to cervical OPLL with multiple spinal lesions.

Effect of primary flocculant type on a two-step flocculation process on iron ore fine tailings under alkaline environment

Dewatering of fine tailings is one of the major challenges faced by the mining and mineral processing industries worldwide. In order to facilitate the separation of released water and solid sediments, different kinds of polymeric flocculants and their combinations have been widely used. A two-step flocculation experiment using two separate primary flocculants in alkaline environment was carried out in this study. The underflow concentration of the two-step flocculation process was higher than that of any single flocculant. Compared to the widely-used flocculation process with a single polymer flocculant, this two-step process could not only significantly improve the total water recovery rate of the slurry, it could also produce a full re-growth of flocs. The first part of the study compared the effects of adding 2 different flocculants to the slurry under alkaline conditions: a non-ionic flocculant, and an anionic flocculant. Compared to the anionic flocculant, the addition of the non-ionic flocculant resulted in a more compact structure and a higher strength by bridging. Conversely, after shear disruption and the addition of the cationic flocculant to the slurry, the re-aggregating broken flocs produced by the anionic flocculant in the first step resulted in a higher reversibility, the formation of a closer and more complex floc structure, and consequently a higher total water recovery rate. This was achieved by drastically re-aggregating broken flocs through the addition of a cationic flocculant that neutralized the charge of the slurry, which in turn is an indication of significant reversibility of the floc break-up process. The dosage of the secondary flocculant had an optimal value to achieve the maximum total water recovery rate. If the dosage exceeded the optimal value, the interaction between the flocculant molecules adsorbed on the same floc occured, which hindered the re-aggregation of flocs and even reduced the secondary water recovery of the slurry.

Experimental Study on the Influence Factors of the Recovery Rate of the Braking Energy of Electric Control & Hydro-Drive Hybrid Vehicle

It is important to improve the fuel economy and environmental protection of the hybrid vehicles by using the energy regenerative braking system to realize the braking energy recovery. In order to confirm the main factors that affect the recovery rate of the braking energy of the hybrid electric vehicle, according to the theoretical analysis results of the braking energy recovery, the related experiments were designed, and the verified experiments of the braking energy recovery rate under different braking intensity, under different initial pressure of accumulators and under different braking initial speed required finishing. The experimental results showed that when the braking intensity was 0.4, the initial pressure of the accumulators was 19MPa and the braking initial speed was 300rpm, the maximum recovery rate of braking energy can be reached by the experiment, which can reach 83.33%.

Mechanisms of temper embrittlement and recovery in cast HY-80 high-strength low-alloy steel

To better understand the mechanisms and rate of temper embrittlement in cast HY-80 high-strength low-alloy steel, samples were subjected to embrittlement and recovery treatments after a typical industrial heat treatment. The embrittlement rate was studied between 315 and 565 °C at varied logarithmic time intervals up to 10000 min. The embrittlement recovery rate was studied between 593 and 704 °C at logarithmic time intervals up to 1000 min. Metallographic and computational work for these samples supports a conclusion that the observed embrittlement and subsequent recovery cannot be solely explained by the segregation of phosphorus and other embrittling elements to grain boundaries as has been previously suspected in this alloy system. Rather it is shown that alloy carbides such as M23C6 play a key role in embrittlement, whereas carbide coarsening and/or nucleation at the prior austenite grain boundaries and in the bulk in the embrittling temperature range. The evolution of these carbides serves both to create initiation sites for cleave and depletes the matrix of Mo, which is a P scavenger. Recovery from embrittlement is thus proposed to be related to both the removal of P from the boundary and the dissolution of carbides from the boundary. Earlier work showing the suspected maximum embrittlement rate occurs at 482 °C with the maximum recovery rate at 648 °C has been rigorously confirmed for a high carbon equivalent cast chemical composition.

Maximisation of oil recovery from an oil-water separator sludge: Influence of type, concentration, and application ratio of surfactants

Worldwide the generation of oil sludges is approximately 160 million metric tonnes per annum. The washing of oil sludge with surfactant solutions can be used to recover the oil and reused as a feedstock for fuel production. There is a need to establish the influence of the surfactant type, concentration, and application (surfactant to oil sludge, S/OS) ratio to oil sludge for the maximisation of oil recovery. This study presented the oil recovery rates from the washing of an oil-water separator sludge using surfactants, Triton X-100, sodium dodecyl sulphate (SDS), Tween 80, rhamnolipid, and Triton X-114. The surfactants were characterised by critical micelle concentration (CMC), micelle size, and surface activity. A Taguchi experimental design was applied to reduce the number of experimental runs. In general, Triton X-100 and X-114, and rhamnolipid had higher micelle sizes and surfactant activities which resulted in higher oil recoveries. The key role of the surfactants in the washing was evidenced because the ORR values with the surfactants were significantly higher than the value with the control with no surfactant solution. The S/OS ratio was the factor with the largest effect on the Taguchi signal-to-noise ratio (an indicator of variation) of the oil recovery rate. The levels with the maximum recovery rate were 1:1 S/OS, 2CMC of surfactant concentration and Triton X-100 (32% ± 5), Triton X-114 (30% ± 7), and rhamnolipid (29% ± 8). In conclusion, less surfactant solution (1:1 S/OS) and low surfactant concentration (≤2CMC) provided the maximum oil recovery from this type of oil sludge. To our knowledge, no previous study with surfactants has reported low oil recovery values at high S/OS ratios in the oil sludge washing.

A recycling culture of Neochloris oleoabundans in a bicarbonate-based integrated carbon capture and algae production system with harvesting by auto-flocculation

BackgroundA bicarbonate-based integrated carbon capture and algae production system (BICCAPS) uses carbonate to capture CO2 and produce bicarbonate for alkalihalophilic microalgal cultivation. In this process, carbonate is regenerated and re-used for CO2 capture. However, a practical example of a recycling culture to prove its feasibility is still absent.ResultsTo reach this goal, a recycling culture of Neochloris oleoabundans was created in this study. The effect of bicarbonate concentration on N. oleoabundans growth showed that the highest productivity was obtained at 0.3 mol L−1, but the highest apparent carbon utilization efficiency was obtained at 0.1 mol L−1. The harvest of algal biomass was tested with alkaline flocculation, which is induced by high pH due to bicarbonate consumption. The result showed that the maximum recovery rate of 97.7 ± 0.29% was reached with a supplement of 20 mM Ca2+. Compared with this, alkaline flocculation without Ca2+ also resulted in a high recovery rate of up to 9 7.4± 0.21% in culture with 0.7 mol L−1 bicarbonate. In recycling culture, the spent medium was bubbled with CO2 and re-used for algal culture. After eight times of recycling, biomass productivity in recycling culture with 0.1 and 0.3 mol L−1 bicarbonate was 0.24 and 0.39 g L−1 day−1, respectively, higher than the 0.20 and 0.30 g L−1 day−1 in the control. The apparent carbon utilization efficiencies achieved in these semi-continuous cultures with 0.1 mol L−1 bicarbonate were 242 ± 3.1 and 266 ± 11% for recycling and control culture, respectively, while those with 0.3 mol L−1 bicarbonate were 98 ± 0.78 and 87 ± 3.6%, respectively.ConclusionsThis study proved the feasibility of BICCAPS recycling culture with the first practical example. More importantly, the produced algal biomass can be harvested without any flocculant supplement. Thus, this process can reduce both culturing and harvesting costs in algal biomass production.

Development of aptamer fluorescent switch assay for aflatoxin B1 by using fluorescein-labeled aptamer and black hole quencher 1-labeled complementary DNA.

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins and draws great concern in health and food safety. A DNA aptamer against AFB1 having a stem-loop structure shows high binding affinity to AFB1 and promise in assay development for AFB1 detection. Based on the structure-switching property of theaptamer, we report an aptamer fluorescence assay for AFB1 detection. Aptamer with fluorescein (FAM) label at 5' end was used as affinity ligand, while its short complementary DNA (cDNA) with BHQ1 (black hole quencher 1) label at 3' end was used as a quencher. In the absence of AFB1, FAM-labeled aptamer hybridized with BHQ1-labeled cDNA, forming a duplex of cDNA and aptamer, resulting in fluorescence quenching of FAM. When AFB1 bound with aptamer, the BHQ1-labeled cDNA was displaced from aptamer, causing fluorescence restoration of FAM. We tested a series of FAM-labeled aptamers and BHQ1-labeled cDNAs with different lengths. The lengths of the aptamer stem and the cDNA, Mg2+ in binding buffer, and temperature had significant influence on the performance of the assay. Under optimized conditions, we achieved sensitive detection of AFB1 by using a 29-mer FAM-labeled aptamer and a 14-mer BHQ1-labeled cDNA, and the detection limit of AFB1 reached 0.2nM. The maximum fluorescence recovery rate of FAM-labeled aptamer caused by AFB1 was about 69-fold. This method enabled the detection of AFB1 in complex sample matrix, e.g., diluted wine samples and maize flour samples. This aptamer-based fluorescent assay for AFB1 determination shows potential for broad applications. Graphical abstract ᅟ.

In situ synthesis of polyurethane scaffolds with tunable properties by controlled crosslinking of tri-block copolymer and polycaprolactone triol for tissue regeneration

Mimicking the mechanical properties of native tissues is a critical criterion for an ideal tissue engineering scaffold. However, most biodegradable synthetic materials, including polyester-based polyurethanes (PUs), consist of rigid polyester chains and have high crystallinity. They typically lack the elasticity of most human tissues. In this study, a new type of biodegradable PU with excellent elasticity was synthesized based on the controlled crosslinking of poly(ester ether) triblock copolymer diols and polycaprolactone (PCL) triols using urethane linkages. Three-dimensional (3D) porous scaffolds with a defined geometry, tunable microstructures, and adjustable mechanical properties were synthesized in situ using an isocyanate-ended copolymer, a tri-armed PCL, and a chain extender. The mechanical properties of the scaffolds can be easily tuned by changing the ratio of reactants, varying the solution concentration, or using a porogen. Notably, all of these scaffolds, although mostly made of rigid PCL chains, showed remarkable elasticity and cyclical properties. With an optimized molecular design, a maximum recovery rate of 99.8% was achieved. This was because the copolymer provided molecular flexibility while the long chain crosslinking of PCL triol hindered crystallization, thus making the PU behave like an amorphous elastic material. Moreover, the in vitro cell culture of 3T3 fibroblasts and MG63 osteoblast-like cells confirmed the biocompatibility of these PU scaffolds and revealed that scaffolds with different stiffnesses can stimulate the proliferation of different types of cells. All of these attributes make PU scaffolds extremely suitable for the regeneration of tissues that experience dynamic loading.

Optimization of drying conditions and components to reduce wall sticking during spray drying of infant formula milk

Wall sticking, which greatly reduces productivity and product quality, has been a big challenge of spray drying. Structure of drying tower and atomizer, as well as drying conditions are the main influencing factors. This research explored the possibility to reduce wall sticking by optimizing drying conditions and components to obtain higher recovery rate of powdered infant formula milk (PIFM). Response surface experimental results indicated that inlet air temperature (T), feed concentration (C), feeding speed (S), as well as interaction term of TC and quadratic terms of C2 and S2 had significant influences on recovery rate for determined milk formula. According to mixture experiments at optimized drying conditions, whey protein (P), fat (F) and lactose (L) contents, as well as interaction term FL had significant effects on recovery rate. Positive effects were observed for F and L contents on recovery rate, while negative effects were observed for P and FL. Under the optimized drying condition of 136°C, 19.80% and 4.07 mL/min, respectively, for T, C and S, the maximum recovery rate of 58.98% was obtained for PIFM with P, F and L content of 18%, 31% and 51%, respectively. Wall sticking phenomena could be reduced by optimizing drying conditions and mildly adjusting components of infant formula milk. Keywords: spray drying, drying condition, wall sticking, inlet temperature, feed concentration, feeding speed, powder recovery rate, infant formula milk DOI: 10.25165/j.ijabe.20181102.2788 Citation: Lin Y W, Liu Y H, Wang L, Xie Y K, Gao Z J, Wang S J. Optimization of drying conditions and components to reduce wall sticking during spray drying of infant formula milk. Int J Agric & Biol Eng, 2018; 11(2): 214–218.

Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. Here, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1 m simultaneous airborne imaging spectroscopy and LiDAR and 2 m satellite multi-spectral imagery) to separate canopy recovery from understory recovery would enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal scales. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management and constraining/benchmarking fire effect schemes in ecological process models.

The effect of annealing treatment on microstructure and shape memory behavior of Ti-Ta-Zr thin films

Ti-Ta-Zr thin films are considered to be promising high-temperature shape memory materials with operation temperature above 100 °C. The effects of annealing treatment on microstructure and shape memory behavior of Ti-Ta-Zr thin films were investigated. The Ti-Ta-Zr thin films under different annealing conditions were all turned out to be α″ phase at room temperature while the microstructures were distinct. The shape memory effect increased with the decreasing of annealing temperature with the maximum shape memory recovery rate of 65% after annealing at 550 °C for 2 min. When the grain size is 8 nm, shape memory effect disappeared.

Study of effective utilization of iron ore sinter through arc plasma

Generation of fines is common in mining, sizing, and beneficiation and also in high-temperature metallurgical processes as the disintegration of agglomerate/compact occurs. Extraction of metallic iron from ore fines is one of the challenging aspects of iron making industries as the liberation of fines blocks, the charge burden porosity and hence hinders the reduction rate. Along with size factor, mineral composition plays a vital role in the extraction process; particularly silica. As silica has the very high tendency towards iron oxide, at comparatively low temperature, the activity of silica should be suppressed to prevent silicate phases. Adjustment of such conditions is controlled by addition of lime, but sometimes excessive slag generation increases the cost of production. In the present work, carbothermic reduction of partially reduced iron bearing pellets has been melted through 20 KW DC arc plasma furnace, and a comparative study has been made for considering different slag chemistry approaches. Pellets as aforementioned are made available from Patnaik Steel and Alloys Ltd, Odisha, having high silica content ore fines (of about 8.6%) as obtained from the chemical analysis. X-Ray analysis and optical image analyzer result of sinter thus obtained reveal that fayalite phase has major fractional value. Smelting works were done for sinter with/without adjustment of slag chemistry, where argon and nitrogen were used as plasma forming gases. A range of recovery rates (between 87-94%) is achieved by charge composition, ionizing gases, and smelting duration. It is observed that use of nitrogen as plasma forming gas increases the recovery rate than that of using only argon plasma; due to high energy flux of nitrogen which increases the enthalpy due to its diatomicity. A maximum recovery rate of about 94% is achieved for process duration of 13minutes utilizing nitrogen plasma. Smelting of charge with the addition of hydrated lime targeting melilite as final slag resulted in the formation of metallic iron as confirmed from XRD and XRF analyses. In the other hand, ferrosilicon is liberated in the metallic parts where smelting of charge was done without adjustment of slag chemistry. Both metal and slag thus obtained are characterized by XRD, XRF, microhardness and wet chemical analysis suitably.

Theoretical prediction and validation of cell recovery rates in preparing platelet-rich plasma through a centrifugation.

In the present study, we propose a theoretical framework to predict the recovery rates of platelets and white blood cells in the process of centrifugal separation of whole blood contained in a tube for the preparation of platelet-rich plasma. Compared to previous efforts to optimize or standardize the protocols of centrifugation, we try to further the physical background (i.e., based on the multiphase flow phenomena) of analysis to develop a universal approach that can be applied to widely different conditions. That is, one-dimensional quasi-linear partial differential equation to describe the centrifugal sedimentation of dispersed phase (red and white blood cells) in continuous phase (plasma) is derived based on the kinematic-wave theory. With the information of whole blood volume and tube geometry considered, it is possible to determine the positions of interfaces between supernatant/suspension and suspension/sediment, i.e., the particle concentration gradient in a tube, for a wide range of centrifugation parameters (time and acceleration). While establishing a theory to predict the recovery rates of the platelet and white blood cell from the pre-determined interface positions, we also propose a new correlation model between the recovery rates of plasma and platelets, which is found to be a function of the whole blood volume, centrifugal time and acceleration, and tube geometry. The present predictions for optimal condition show good agreements with available human clinical data, obtained from different conditions, indicating the universal applicability of our method. Furthermore, the dependence of recovery rates on centrifugal conditions reveals that there exist a different critical acceleration and time for the maximum recovery rate of platelets and white blood cells, respectively. The other parameters such as hematocrit, whole blood volume and tube geometry are also found to strongly affect the maximum recovery rates of blood cells, and finally, as a strategy for increasing the efficiency, we suggest to dilute the whole blood, increase the whole blood volume with a tube geometry fixed.

Biosorption of heavy metals from aqueous solution by the novel biosorbent Pectobacterium sp. ND2

In this study, the biosorption of heavy metal ions such as Cd(II), Cu(II), Zn(II), and Pb(II), was investigated using a new bacterial species isolated from the soil of the industrial zone of Xuzhou city. Sequence analysis of the 16S rRNA gene showed that the bacteria were Pectobacterium sp., denoted as ND2. In order to optimize the conditions for the biosorption of heavy metal ions, the effects of various physico‐chemical parameters were assessed, including pH value, contact time, initial metal ion concentration, biosorbent dose, and temperature. Under the optimal condition, the maximum ion biosorption capacity (mg/g) of Pectobacterium sp. ND2 was ranked in the order of Cd(II)(44.9 mg/g) > Cu(II)(38.6 mg/g) > Zn(II)(34.2 mg/g) > Pb(II)(31.2 mg/g). Both Langmuir and Freundlich isotherm models were used to explain this adsorption phenomenon. The FTIR analysis of surface chemical functional groups of Pectobacterium sp. ND2, revealed the involvement of carboxyl, amino and phosphate groups in the adsorption process. In addition, adsorption–desorption studies indicated that 0.1M nitric acid is an efficient desorbent for Cd(II), Cu(II), Zn(II), and Pb(II) ions, with maximum recovery rates of more than 90%. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 968–974, 2018

Lead recovery from waste CRT funnel glass by high-temperature melting process

In this research, a novel and effective process for waste CRT funnel glass treatment was developed. The key to this process is removal of lead from the CRT funnel glass by high-temperature melting process. Sodium carbonate powder was used as a fusion agent, sodium sulfide serves as a catalytic agent and carbon powder acts as reducing agent. Experimental results showed that lead recovery rate increased with an increase in the amount of added sodium carbonate, sodium sulfide, carbonate, temperature and holding time initially, and then reached a stable value. The maximum lead recovery rate was approximately 94%, when the optimum adding amount of sodium carbonate, sodium sulfide, carbonate, temperature and holding time were 25%, 8%, 3.6%, 1200°C and 120min, respectively. In the high-temperature melting process, lead silicate in the funnel glass was firstly reduced, and then removed. The glass slag can be made into sodium and potassium silicate by hydrolysis process. This study proposed a practical and economical process for recovery of lead and utilization of waste glass slag.

Regenerative Braking Control Strategy of Electric-Hydraulic Hybrid (EHH) Vehicle

A novel electric-hydraulic hybrid drivetrain incorporating a set of hydraulic systems is proposed for application in a pure electric vehicle. Models of the electric and hydraulic components are constructed. Two control strategies, which are based on two separate rules, are developed; the maximum energy recovery rate strategy adheres to the rule of the maximization of the braking energy recovery rate, while the minimum current impact strategy adheres to the rule of the minimization of the charge current to the battery. The simulation models were established to verify the effects of these two control strategies. An ABS (Anti-lock Braking System) fuzzy control strategy is also developed and simulated. The simulation results demonstrate that the developed control strategy can effectively absorb the braking energy, suppress the current impact, and assure braking safety.

Ureido-modified macroporous hollow silica microspheres for recovery of Wilkinson's catalyst in hydrogenated nitrile butadiene rubber

Hydrogenated nitrile butadiene rubber (H-NBR), which is obtained by the selective hydrogenation of nitrile butadiene rubber (NBR), has attracted great interests in many industrial fields. However, the recovery of the catalyst remains a challenge in the homogeneous catalytic hydrogenation of NBR, restricting its industrial production. In the present work, ureido-modified macroporous hollow silica microspheres were designed for the recovery of the Rh-based catalyst, with Wilkinson's catalyst (RhCl(P(C6H5)3)3) as an example, in the homogeneous catalytic hydrogenation of NBR. After the effects of the adsorbent loading, adsorption parameters (temperature, agitating speed and time), and separation condition (centrifugal speed and time) on the Rh recovery rate were optimized in detail, a maximum Rh recovery rate of 92.2% was achieved.

The use of hydrate formation for the continuous recovery of ethylene and hydrogen from fluid catalytic cracking dry gas

Abstract A large amount of fluid catalytic cracking (FCC) dry gas, which contains high concentrations of ethylene and hydrogen, is used as low heat value fuel or simply flared every year, resulting in not only a waste of resources but also greenhouse gas emission. This study provides a continuous hydrate separation technology to solve this problem. The FCC dry gas flow was continuously separated into two gas flows: a C 2 H 4 -rich, low H 2 stream and a residual gas stream with low C 2 H 4 and high H 2 contents. This paper experimentally investigated the effects of temperature and the concentration of tetra butyl ammonium bromide (TBAB) on the hydrate forming pressure of FCC dry gas, the time evolution of the gas compositions and the gas flow rates during long-term operation of the hydrate-based separation, and the effects of different influential factors on the separation. The concentration of C 2 H 4 was increased from 47.17% to 71.56%, and the maximum recovery rate of C 2 H 4 reached 90.47%. The maximum separation factor of ethylene was 8.13. The concentration of H 2 was increased from 31.08% to 63.60%, and the maximum recovery rate of H 2 was 91.45%. The maximum separation factor of hydrogen was 8.87.

Extraction of lead from waste CRT funnel glass by generating lead sulfide – An approach for electronic waste management

Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process.

Evaluation of frothers based on properties of the solids/liquid/gas system

A methodology of selection of frothers for flotation process is presented in the paper. It is based on performing a series of fractionating flotation tests of a considered material at different doses of a selected frother and calculation of the mass balance of the process. Next, three steps are performed. The first one is determination of the frother dose and kinetic constant or specific rate, using the flotation limits plot relating maximum recovery and process rate, both at a selected maximum recovery of the considered material component. The second step is finding selectivity of separation by using the upgrading Fuerstenau plot, while the third element is frothers comparison plot in the form of selectivity versus process kinetics, at a selected maximum recovery, and also versus frother dose, for choosing the most suitable frother.