Experimental Study of Mineral Salts Concentration in Seawater

Mineral salts are of great importance on the regulation of different metabolic activities of living organisms. The well-functioning of the body depends on mineral salts. These salts, existing naturally in small quantity in our diverse diets （grains, legumes, fruit, tea, egg, etc.）, are concentrated in seawater. In this paper, the indirect fi＇eezing is used as a concentration process to recover the most of salt minerals naturally present in seawater. Freezing is known as a purification process, but this paper recovers the brine instead of the formed ice. A 3.5% salinity solution with an appropriate setup is used to recover the maximum of salt in the brine. The work aims to develop a process for freezing salt concentration on cold walls. The influence of operating parameters has highlighted the important role of the cooling ramp and stay time on the salt concentration produced.

Progress and Prospects of Salt Lake Research in China

China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate （salt forming） have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits： the atlas （1：2500000） of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of ＂Continental Potash Deposition Theory＂; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, the kurnakovite bed in Lake Nyer, and the corresponding model of borate deposition from the cooling and dissolution of boron rich brines was proposed based on principles of geology, physics and chemistry. The anti-floatation-cold crystallization method developed independently has improved the capacity of KCI production to 3 million tons per year for the Qarham, serving the famous brand of potash fertilizer products. One 1.2 million ton K-sulfate production line, the biggest in the world, has been built in Lop Nor, and K-sulfate of about 1.6 million tons was produced in 2015. Supported by the new technology, i.e. brine preparation in winter-cooling-solarization-isolation-lithium deposition from salt gradient solar pond＂ the highest lithium production base at Zabuye Lake （4421 m）, Tibet, has been established, which is the first lithium production base in China that reaches the year production of 5000 tons of lithium carbonate. The concept of Salt lake agriculture （Salt land agriculture） has been established based on the mass growth of Dunaliella and other bacillus-algae and the occurrence of various halophytes in saltmarsh and salt saline-alkali lands, finding a new way to increase arable lands and develop related green industry in salt rich environments. Finally this paper presents some new thoughts for the further research and development on salt science, and the further progress in salt science and technology will facilitate the maturing of the interdisciplinary science ＂Salinology＂.

Phase Chemistry Study of the Zabuye Salt Lake Brine:Isothermal Evaporation at 15℃ and 25℃

Zabuye Salt Lake in Tibet,China is a carbonate-type salt lake,which has some unique characteristics that make it different from other types of salt lakes.The lake is at the latter period in its evolution and contains liquid and solid resources.Its brine is rich in Li,B,K and other useful minor elements that are of great economic value.We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15℃and 25℃.The crystallization sequence of the primary salts from the brine at 25℃is halite（NaCl）→aphthitalite （3K_2SO_4·Na_2SO_4）→zabuyelite（Li_2CO_3）→trona（Na_2CO_3·NaHCO_3·2H_2O）→thermonatrite （Na_2CO_3·H_2O）→sylvite（KCl）,while the sequence is halite（NaCl）→sylvite（KCl）→trona （Na_2CO_3·NaHCO_3·2H_2O）→zabuyelite（Li_2CO_3）→thermonatrite（Na_2CO_3·H_2O）→aphthitalite （3K_2SO_4·Na_2SO_4） at 15℃.They are in accordance with the metastable phase diagram of the Na~＋,K~＋-Cl^-, CO_3^（2-）,SO_4^（2-）-H_2O quinary system at 25℃,except for Na_2CO_3·7H_2O which is replaced by trona and thermonatrite.In the 25℃experiment,zabuyelite（Li_2CO_3） was precipitated in the early stage because Li_2CO_3 is supersaturated in the brine at 25℃,in contrast with that at 15℃,it precipitated in the later stage.Potash was precipitated in the middle and late stages in both experiments,while boron was concentrated in the early and middle stages and precipitated in the late stage.

Phase Chemistry Study of the Dangxiongcuo Salt Lake Brine:Isothermal Evaporation at 25℃

Production of lithium carbonate from brines has become the dominate trend in the world from the beginning of this century.Dangxiongcuo,a carbonate-type salt lake,is located in the interior of the Tibetan Plateau,China.As a salt lake deposit,rich in Li,B,K and other useful trace

Natural Evaporation of Dangxiongcuo Salt Lake Spring Brine in Tibet,China

1 Introduction Dangxiongcuo salt lake(Figure 1),which is located in the southwest of Tibet,China,is rich in valuable mineral elements like lithium,potassium,boron,rubidium,caesium

Optimization of Cowpea Dry Grain Yield through the Stimulation of the RNA Synthetic Activity of NADH-Glutamate Dehydrogenase

Several potentially practical biochemical processes in plant systems still remain hidden, especially the NADH-glutamate dehydrogenase (GDH) synthesis of nongenetic code-based RNA that optimizes crop nutritious yield by degrading superfluous genetic code-based RNA. In continued characterization of the biochemistry of cowpea grain yield, GDH was purified by electrophoresis from seeds of cowpea treated with solutions of stoichiometric mixes of mineral salts. The GDH was made to synthesize RNAs in the amination (α-KG/NADH/) and then in the deamination (L-Glu/NAD+) direction. The initial product RNAs were captured and sequenced. The grand challenge was to discover the specific molecular roles of the redox enzyme in the optimization of cowpea grain yields. In the amination direction, the GDH hexamers synthesized plus-RNA, but in the deamination direction, they synthesized minus-RNA. The plus-RNAs and minus-RNAs were homologous to about the same numbers of different mRNAs encoding the key enzymes that regulate photosynthesis;saccharide biochemistry and glycolysis;phenylpropanoid biosynthesis;nodulation nitrogen fixing processes;dehydrin drought and glutathione environmental stress resistance processes;purine, pyrimidine, DNA, RNA and essential amino acid biosynthesis;storage protein vicilin accumulation;isoflavone earliness of cowpea maturity;peroxidase synthesis of lignin and sequestration of CO2 to enrich soil organic carbon contents;triglyceride physiology in the biosynthesis of bioactive compounds that render cowpea resistant to insects and fungi;etc., all of which constitute the GDH chemical pathways for discrimination of biochemical, physiological, metabolic, genetic reactions;and optimization of cowpea dry grain yields. Each stoichiometric mix of mineral salts produced optimally yielding biochemical variant of purple hull cowpea;the K + K + K mix was spectacular because it increased the grain yield to 7598 kg from the 3644 kg·ha-1 in the control cowpea. Optimized nutritious staple crop yield buttresses food security. The synthesis of plus-RNA in amination and minus-RNA in deamination is an economic tactical plan in biochemistry for the selection of superfluous mRNAs that would be degraded to assure the survival of cowpea growing under unfavorable environmental conditions.