Extraction Of Boron Research Articles

Micronutrient concentrations vary between peat–mineral mix and substrates in revegetated sites in the Alberta oil sands

Adequate supply of micronutrients is essential for plant growth in reclaimed sites in the Athabasca oil sands region. The objectives of this study were to determine boron, iron, manganese, copper, and zinc concentrations in peat–mineral mix (PMM), tailings sand (TS), and overburden (OB) materials and to assess whether lodgepole pine (Pinus contorta) planted on PMM over TS and white spruce (Picea glauca) planted on PMM over OB had low foliar micronutrient concentrations. Micronutrient concentrations determined using LiNO3 and Mehlich-3 extractions were different between PMM and TS in the pine sites while only LiNO3 extractable boron was different between PMM and OB in the spruce sites (p iron > manganese > zinc > copper in all soil layers with concentrations ranging from 0.04 to 39.56 μg g−1. The low foliar concentration of copper in pine and spruce was consistent with low LiNO3 extractable copper in the soil in both the pine and spruce s...

Leaching kinetics of ulexite ore in aqueous medium at different CO 2 partial pressures

This manuscript presents a study regarding the leaching kinetics of ulexite (Na2O.2CaO.5B2O3.16H2O) under different CO2 partial pressures in aqueous media. The effects of the reaction temperature, particle size, CO2 partial pressure, solid-liquid ratio, and agitation speed were investigated in the boron extraction from the ore. As a result of the experimental studies, it was found that the leaching rate increased with the rise in the reaction temperature and CO2 partial pressure, and decreased with the increase in the particle size and solid-liquid ratio. The reaction temperature was found to be a significant parameter affecting the leaching rate, which varied from 13% to 97% between 303 and 393 K. Agitation speed appears to have no significant effect on the leaching rate. By using several empirical kinetic models to correlate the experimental data, it was found that the leaching rate fits to the Avrami Model. The activation energy of the process is found to be 21.1 kJ.mol-1.

СОВРЕМЕННЫЕ ТЕХНОЛОГИИ ИЗВЛЕЧЕНИЯ БОРА ИЗ ВОДНЫХ РАСТВОРОВ

СОВРЕМЕННЫЕ ТЕХНОЛОГИИ ИЗВЛЕЧЕНИЯ БОРА ИЗ ВОДНЫХ РАСТВОРОВ

Research on boron recovery from sulfate-type saline lakes with a novel dilution method

A novel dilution method was developed to extract boron from sulfate-type salt lake brine in the Qinghai Tibet plateau. The boron-concentrated brine was prepared by evaporation after magnesium removal using Na2SO4·10H2O solid. The extraction process parameters such as boron concentration, dilution ratio, temperature, initial precipitation time, aging time, and extraction efficiency of boron were tested. The results showed that the solution pH after dilution with deionized water increased from 4.2 to 8.0, indicating dissociation of polyborate ions in brine by hydrolysis to give monoborate species and hydroxide ions. The initial precipitation time and aging time were observed to be strongly influenced by the boron concentration, dilution ratio, and temperature. A low temperature, high boron concentration and moderate mass dilution ratio (water/brine) were beneficial to boron extraction, allowing for an extraction efficiency of more than 80%. The only salts that precipitated from diluted brine were magnesium borates. The obtained results indicated the application potential of the novel technology of boron extraction from salt lake brine.

Experimental studies in the sorptive extraction of boron and lithium from thermal waters

We studied the extraction of boron and lithium from prepared and industrial solutions using industrial ionites ATsD-4-1p, AV-16 GS, AN-3, and AV-17-8 and by modified zeolites from the Yagodnoe field, Kamchatka. The modification was performed using aluminum hydroxide, hydrochloric hydroxylamine, or urotropin. We found that when modified with Al(OH)3, zeolite shows selectivity with regard to lithium ions. When modified with hydrochloric hydroxylamine or with urotropin zeolites can be used for sorption of boric acid from naturally occurring and industrial solutions. The sorptive capacity of the modified zeolites is 30% higher on average compared with that of industrial ionites.

Comparison of boron uptake, translocation, and accumulation in reed, cattail, and vetiver: an extremely boron-tolerant plant, vetiver

Aims Reed (Phragmites australis L.) and cattail (Typha latifolia L.) have been used to extract boron (B) from wastewater streams by accumulating B in plant tissues. Vetiver (Chrysopogon zizanioides L.) is a very useful species in phytoremediation; however, there is little information on its ability to accumulate and tolerate B. Differences in B tolerance and accumulation are known for many species, but the underlying mechanisms are still poorly investigated. The objectives of this study were to identify differences in B tolerance and accumulation among reed, cattail, and vetiver, and elucidate the underlying physiological mechanisms for improving their use in B phytoremediation.

Physiographic characteristics of agricultural lands and farmers’ soil fertility management practices in Wolaita zone, Southern Ethiopia

Understanding the landscape features of agricultural lands and soil management practices is pertinent to verify the potential and limitations of the soil resources; and devise relevant land management strategies. However, information is lacking in Wolaita, Southern Ethiopia. Thus, this study aimed at investigating the physiographic characteristics of agricultural lands, farmers’ soil fertility management practices and their influences on soil fertility and crop productivity was conducted. The survey involved 789 randomly sampled agricultural lands. Soil sample as well as data on slope, topography, land use, crop rotation, fallowing, cropping intensity, crop residue management, fertilizer use and farmers’ estimated crop yield were collected and evaluated. The result indicated that agriculture has been practiced under diverse slope positions (1–58%). This significantly influenced most of soil physico-chemical properties in which an increase in soil bulk density, and decrease in available phosphorous, exchangeable calcium, extractable boron, copper, iron and zinc with an increase in slope positions were recorded. Furthermore, continuous cultivation without any fallow periods and complete crop residue removal (96%) were common practices. Fertilizer use was not sufficient. The average use (kg ha−1) was 30 and 9 for di-ammonium phosphate (DAP) and urea, respectively, and about 89% of study area received manure below 1.5 t ha−1. All these limitations made farmers to experience lower crop yield than the national average estimates. Based on the result, it is possible to conclude that the following soil management interventions such as soil conservation, application of sufficient organic and inorganic fertilizers are recommended to restore the soil fertility and improve crop productivity.

The chemistry and isotopic composition of waters in the low-enthalpy geothermal system of Cimino-Vico Volcanic District, Italy

Geothermal energy exploration is based in part on interpretation of the chemistry, temperature, and discharge rate of thermal springs. Here we present the major element chemistry and the δD, δ18O, 87Sr/86Sr and δ11B isotopic ratio of groundwater from the low-enthalpy geothermal system near the city of Viterbo in the Cimino-Vico volcanic district of west-Central Italy. The geothermal system hosts many thermal springs and gas vents, but the resource is still unexploited. Water chemistry is controlled by mixing between low salinity,HCO3-rich fresh waters (<24.2°C) flowing in shallow volcanic rocks and SO4-rich thermal waters (25.3°C to 62.2°C) ascending from deep, high permeability Mesozoic limestones. The (equivalent) SO4/Cl (0.01–0.02), Na/Cl (2.82–5.83) and B/Cl ratios (0.02–0.38) of thermal waters differs from the ratios in other geothermal systems from Central Italy, probably implying a lack of hydraulic continuity across the region. The δ18O (−6.6‰ to −5.9‰) and δD (−40.60‰ to −36.30‰) isotopic composition of spring water suggest that the recharge area for the geothermal system is the summit region of Mount Cimino. The strontium isotope ratios (87Sr/86Sr) of thermal waters (0.70797–0.70805) are consistent with dissolution of the Mesozoic evaporite-carbonate units that constitute the reservoir, and the ratios of cold fresh waters mainly reflect shallow circulation through the volcanic cover and some minor admixture (<10%) of thermal water as well. The boron isotopic composition (δ11B) of fresh waters (−5.00 and 6.12‰) is similar to that of the volcanic cover, but the δ11B of thermal waters (−8.37‰ to −4.12‰) is a mismatch for the Mesozoic reservoir rocks and instead reflects dissolution of secondary boron minerals during fluid ascent through flysch units that overlie the reservoir. A slow and tortuous ascent enhances extraction of boron but also promotes conductive cooling, partially masking the heat present in the reservoir. Overall data from this study is consistent with previous studies that concluded that the geothermal system has a large energy potential.

MODIFICACIÓN DE POLIURETANOS QUÍMICAMENTE ACTIVOS MEDIANTE POLI(VINILBENCIL-N-METIL-DGLUCAMINA) PARA LA RETENCIÓN DE BORO

El boro es un micronutriente esencial en el desarrollo, fortalecimiento y crecimiento de las plantas; sin embargo, este elemento posee un estrecho rango de esencialidad conllevando a que la determinación de los contenidos de boro en los suelos sea de vital importancia con el fin de garantizar que su fitodisponibilidad permanezca en un rango óptimo de concentraciones. En la actualidad, el desarrollo de materiales poliméricos basados en poliuretanos (PUs) con capacidad controlada de carga y descarga, alta resistencia a la intemperie, y que permitan la dosificación controlada y extracción de boro de las aguas de riego son de gran interés para aplicaciones en agricultura. Así, el objetivo del presente trabajo fue desarrollar polímeros de injerto basados en N-metil-D-glucamina (NMDG) a partir de matrices de PU químicamente activas con capacidad de retención de boro. Para esto, se sintetizó el vinilbencil-N-metil-Dglucamina (VbNMDG) a partir del cloruro de vinilbencilo y NMDG.&#x0D; Posteriormente, se llevó a cabo la uretanización del VbNMDG con metilen difenil diisocianato (MDI); el PU resultante al poseer grupos lábiles, capaces de reaccionar en una segunda etapa vía radicales libres, fue polimerizado para llevar a cabo la formación de polímeros de injerto con cadenas de NMDG. Finalmente, la capacidad de retención de boro se determinó por el método de la azometina-H. Los resultados muestran que estos materiales poseen la capacidad de retener boro y pueden emplearse potencialmente en la fertilización agrícola de este micronutriente.

Interference by Iron in the Determination of Boron by ICP-OES in Mehlich-III Extracts and Total Element Digests of Tropical Forest Soils

ABSTRACTBoron detection in soil extracts by inductively-coupled plasma optical-emission spectrometry (ICP-OES) can be influenced by iron interference, particularly in strongly weathered tropical forest soils. Boron concentrations in Mehlich-III extracts of 230 soils under lowland tropical forest in Panama were markedly overestimated at the most sensitive ICP-OES wavelength (249.772 nm) compared to a less sensitive but interference-free wavelength (208.957 nm) due to iron interference. Hot-water extracts contained insufficient iron to interfere in boron detection, but boron quantification in total element digests was affected strongly by iron interference at 249.772 nm. The relationship between boron overestimation and iron was used to correct a database of 300 Mehlich-III extractable boron measurements made at 249.772 nm for soils from a large forest dynamics plot. We recommend that boron measurements in tropical forest soils by ICP-OES should use the less sensitive 208.957 nm wavelength to avoid interference by extracted iron.

Post-Synthesis Conversion of Borosilicate Zeolite Beta to an Aluminosilicate with Isolated Acid Sites: A Quantitative Distance Analysis by Solid-State NMR

Isolated acid sites were selectively generated by postsynthesis modification of a borosilicate zeolite beta. To this end, samples were prepared with pairs of adjacent boron sites balanced by Ca2+ ions, whereas isolated boron in the zeolite framework was balanced by NH4+ ions. To avoid undesired boron leaching, these ion exchange reactions were carried out in methanol solution rather than in water. Trigonal boron forms near the NH4+ ions by decomposing the latter into NH3 (and a proton), and selective extraction of the trigonal boron is achieved by water treatment, whereas the tetrahedral boron near Ca2+ ions remains in the zeolite framework. The vacancies were refilled with aluminum by treatment with an aqueous Al(NO3)3 solution. Two Bronsted acid sites with 1H chemical shifts of 4.0 and 5.0 ppm exist in the dehydrated samples. 1H–27Al REAPDOR solid-state NMR measurements yield quantitative information on the local H–Al distances of isolated H–Al two-spin and H–Al–Al three-spin systems. The nearest H–Al d...

Innovative method for boron extraction from iron ore containing boron

A novel process for boron enrichment and extraction from ludwigite based on iron nugget technology was proposed. The key steps of this novel process, which include boron and iron separation, crystallization of boron-rich slag, and elucidation of the boron extraction behavior of boron-rich slag by acid leaching, were performed at the laboratory. The results indicated that 95.7% of the total boron could be enriched into the slag phase, thereby forming a boron-rich slag during the iron and slag melting separation process. Suanite and kotoite were observed to be the boron-containing crystalline phases, and the boron extraction properties of the boron-rich slag depended on the amounts and grain sizes of these minerals. When the boron-rich slag was slowly cooled to 1100°C, the slag crystallized well and the efficiency of extraction of boron (EEB) of the slag was the highest observed in the present study. The boron extraction property of the slow-cooled boron-rich slag obtained in this study was much better than that of szaibelyite ore under the conditions of 80% of theoretical sulfuric acid amount, leaching time of 30 min, leaching temperature of 40°C, and liquid-to-solid ratio of 8 mL/g.

Potential of magnesium salt–monoalkylpolyethylene glycol–water systems for use in micellar extraction

Solubilities in MgCl2 (MgSO4, Mg(NO3)2)–syntanol DS-10 (syntanol ALM-10)–water systems have been studied by the visual-polythermal method and the isothermal section method. The liquid–liquid phase separation region was shown to change its topology depending on temperature and the salting-out agent. The salting-out agent anion was shown to influence the cloud point of syntanol solutions. The effect of structure on the ability of syntanol to be salted out by magnesium salts was studied. Optimal temperature and concentration parameters of boron extraction in the studied systems were determined.

Enhancement in extraction of boron and phosphorus from metallurgical grade silicon by copper alloying and aqua regia leaching

The feasibility and optimization of an enhanced boron and phosphorus extraction process, from metallurgical grade silicon (MG-Si), consisting of solvent refining and acid leaching were studied comprehensively. MG-Si was alloyed with copper (Cu), following which, the removal of boron and phosphorus from the Si–Cu alloy by acid leaching was investigated. The results showed that the Cu-alloying process led to the concentration of boron and phosphorus in the Si–Cu alloy phase, which was confirmed to be an important part of their removal. Based on the analysis of acid sensitivity of the Si–Cu alloy phase, it was found that aqua regia was an effective leaching agent for removing the Si–Cu alloy phases from Si grains compared to HCl and HNO3. Addition of copper resulted in the increase in the extraction yield of boron and phosphorus from MG-Si from 21.0 to 58.7% and 23.2 to 42.2%, respectively. The selected Si–Cu powders were within a size range 74–106μm and the leaching was conducted at 70°C for 5h via a three-step sequential acid leaching procedure. Furthermore, the leaching kinetics of boron and phosphorus using aqua regia was observed to be controlled by interfacial transfer and product layer diffusion.

Extraction of boron from salt lake brine using 2-ethylhexanol

A systematic investigation on the extraction of boron from salt lake brine using 2-ethylhexanol as the extractant is reported with an emphasis on the extraction thermodynamics and extraction process design in order to obtain high purity boron product. The extraction parameters were optimized with respect to the time of extraction, volume percentage of extractant, phase ratio, and the concentration of magnesium. Logarithm linear regression revealed an average association constant of 0.7 for 2-ethylhexanol and boric acid. Thermodynamic modeling results indicate that the association is an exothermic, enthalpy driven process. A three-stage countercurrent extraction and stripping was designed in order to assess the process feasibility. Results showed an overall boron extraction efficiency of 99.5% with a purity of 95.5%. In addition, attempts were also made on improving the product purity with a two-stage washing step. These results indicate the application potential of present extraction process.

Extractable boron in some acid soils of India: Status, spatial variability and relationship with soil properties

Extractable boron in some acid soils of India: Status, spatial variability and relationship with soil properties

Assessment of soil boron availability in apple orchards using different extractants

Soil analysis for boron is vital as the range between its deficiency and toxicity is quite narrow and its application slightly above the optimum level may prove toxic to plants. In present study, the extractability of various extractants was assessed in relation to the physicochemical properties of soils. Soil sampling was carried out in 30 orchards in district Kulgam, Kashmir. Four extractants widely used to determine plant-available boron from either acidic or alkaline soils were used. The hot-water-soluble boron (HWSB) extraction procedure was used as a benchmark to observe relative variation in available boron in alternate extractants like calcium chloride-mannitol (CaCl2-mannitol), ammonium acetate and diethylene-triaminepenta-acetic acid-sorbitol (DTP Asorbitol). A significant correlation was found for available B among all the extractants tested, the strongest correlation (r = 0.975** at P≤0.01) was observed between HWSB and DTPA-sorbitol and hence it may substitute the hot water extraction method for estimating plant-available B.

Effect of Na2CO3 on reduction and melting separation of ludwigite/coal composite pellet and property of boron-rich slag

The effects of Na2CO3 on the reduction and melting separation behavior of ludwigite/coal composite pellet, the desulfurization ratio and the property of the separated boron-rich slag were investigated at laboratory scale in the present work. Na2CO3 could improve the reduction rate of the composite pellet to some extent. The melting separation of the composite pellet became increasingly difficult with the increase of Na2CO3 in the pellet due to the sharply increasing of the melting point of slag. The sulfur content of the iron nugget gradually decreased from 0.27% to 0.084% (mass fraction) with the Na2CO3 content in the pellet increasing from 0 to 6%. The efficiency of extraction of boron (EEB) of the slow cooled boron-rich slag decreased from 86.46% to 59.52% synchronously. Na2CO3 had obviously negative effect on melting separation of the composite pellet and boron extraction of the boron-rich slag.

Reduction behavior of boron-bearing iron concentrates by bituminous coal and its magnetic separation

In this study, the effects of temperature and time on the reduction behavior of boron-bearing iron concentrate briquettes were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). Results indicated that reduction temperature played a crucial role in the selective reduction of iron minerals in boron-bearing iron concentrate briquettes with bituminous coal as a reducer. The increase in reduction time facilitated the generation of metallic iron and the grain growth of the metallic phase in the reduced briquettes, which had a beneficial effect on the separation of iron and boron in the subsequent low-intensity magnetic separation process. The magnetic material contained 92.81% Fe with a recovery of 95.58%, while in the boron-rich non-magnetic material, the grade and recovery values of B2O3 were 14.11% and 89.59%, respectively. In addition, the efficiency of extraction of boron of the non-magnetic material was 80.76%. The magnetic material and boron-rich non-magnetic material were good raw materials for steel-making and borax production.

Reduction–melting behaviors of boron-bearing iron concentrate/carbon composite pellets with addition of CaO

Although the total amount of boron resources in China is high, the grades of these resources are low. The authors have already proposed a new comprehensive utilization process of boron-bearing iron concentrate based on the iron nugget process. The present work describes a further optimization of the conditions used in the previous study. The effects of CaO on the reduction–melting behavior and properties of the boron-rich slag are presented. CaO improved the reduction of boron-bearing iron concentrate/carbon composite pellets when its content was less than 1wt%. Melting separation of the composite pellets became difficult with the CaO content increased. The sulfur content of the iron nugget gradually decreased from 0.16wt% to 0.046wt% as the CaO content of the pellets increased from 1wt% to 5wt%. CaO negatively affected the iron yield and boron extraction efficiency of the boron-rich slag. The mineral phase evolution of the boron-rich slag during the reduction–melting separation of the composite pellets with added CaO was also deduced.