AbstractBiocementation using the microbial-induced calcite precipitation (MICP) technique is an environmentally friendly method that imitates the natural cementation phenomenon to improve the behavior of soils. Urea hydrolysis performed by ureolytic ...Practical ApplicationsMICP is a natural method of soil improvement. The microorganisms used for this …
Permeate or distillate from desalination processes is typically void of minerals and alkalinity, inherently acidic and therefore corrosive to water distribution infrastructure. The reintroduction of both minerals and alkalinity is essential for the stabilization of the water before it is sent to consumers making this the last step of the treatment process. Classical water …
PurposeThe main aim of this work was to determine the efficiency and mechanism of iron (Fe)-modified calcite (FMCA) capping for preventing the release of phosphorus (P) from sediments.Methods The ...
Although the substitution for Ca 2+ is likely the main uptake process of these metals into calcite, depending on their ionic radius and charge, trace elements may also be incorporated by adsorption or physical entrapment. Our study shows that unlike laboratory experiments performed under specific conditions, the partitioning of metals between ...
The anionic oleate and cationic amine collector adsorption theories proposed by various researchers are briefly summarized in this section. The adsorption …
This paper presents an efficient method of microbial-induced calcite precipitation (MICP) for cementation of sand particles. First, the influence of initial pH value of the culture medium on the growth of bacteria was discussed. Then, the compressive strength and calcium carbonate content of cemented sand columns with different sand particle sizes were …
To use calcite mud waste generated from the paper production process, calcite mud was treated by calcination and then applied as a sorbent agent to remove phosphorus from an aqueous solution. ... The chemical precipitation technique has attracted attention due to its high removal efficiency and simple process [23–25]. Other research using ...
Calcite: A Key Ingredient in Efficient Cement Manufacturing. The primary use of calcite lies in construction materials, particularly as a raw material for manufacturing cement …
One of the most energy-intensive processes for producing submicron range calcite is stirred media mill. In the present work, numerous operating parameters such as solid mass fraction, grinding media size, media filling ratio, and grinding time have been investigated using a vertical type stirred media mill. The results are evaluated on the basis of mean particle …
Fluorite and calcite were separated with nitrilotriacetic acid (NTA) as a depressant. The single mineral flotation experiment confirmed that with 40 mg/L NaOL and 80 mg/L NTA, the fluorite recovery and calcite recovery were 24.37 and 94.13%, respectively, at pH 9. Meanwhile, in the fluorite-calcite binary mixed ore flotation experiment, the calcite recovery and fluorite …
In this work, N-tetradecyl-isopropanolamine (NTIA) is synthesized and used as a new collector on the flotation separation process of scheelite from calcite to further improve the efficiency of the selective flotation. The effects of NTIA on minerals are investigated through microflotation experiments.
The efficiency of this type of system depends on : the reactivity of the product used (porosity, density); particle size; temperature; the raw water's initial M-alk.; contact time. Figure 45 illustrates an example of the calculation charts …
At SI CaCO 3 > 0, the SSA of calcite mainly determines barrier efficiency, whereas at SI CaCO 3 < 0, the physico-chemical properties of calcite are less important as already discussed. A higher SSA and microporosity, however, accelerate the dissolution process and, consequently, improve the precipitation of Ca–P compounds.
Microbially Induced Calcite Precipitation (MICP) through ureolytic bacteria has been considered as the most straightforward and energy-efficient process for engineering applications. In this paper, the potential of utilizing the waste stream technology along with MICP was discussed. This detailed study concluded that waste streams could ...
Flotation is widely employed as a technique for separating scheelite from calcite [4], [5]. Sodium oleate is frequently utilized as a collector in scheelite flotation [6], [7], yet its selectivity is limited [8], [9]. Consequently, the selection of suitable depressants during the flotation process is essential for enhancing separation efficiency.
The process of microbially induced calcite precipitation (MICP) has recently attracted attention due to its efficiency in the immobilization of heavy metals. Ureolytic bacteria govern the MICP process by hydrolyzing urea into ammonium and carbonate ions as the pH increases due to production of ammonium ions.
This process is significantly enhanced by the surface roughness of the calcite grains (M2066) due to numerous micropores of <2 nm in diameter. ... An efficient calcite barrier can be adapted to specific hydrochemical. Acknowledgements.
During the flotation process, the surface of fluorite and calcite is prone to partial dissolution, which makes the surface ions convert to each other. Moreover, the pH value of the slurry has a greater impact on the conversion of the two minerals. ... Much attention has been paid to the efficient separation of fluorite and calcite. Compared ...
This vaterite could actually be flushed away if not given enough time to redissolve and precipitate as calcite, which would also result in reduced process efficiency. In this study, the determined maximum effective input rate ensured that the injected urea was hydrolyzed by bacteria, and that the precipitated CaCO3 remained in the tested ...
Apache Calcite is a dynamic data management framework that provides a standard SQL parser, validator, and JDBC driver. ... which is the process of finding the most efficient way to execute a query.
In the MICP process, urease plays a major role in urea hydrolysis by a wide variety of microorganisms capable of producing high levels of urease. We also elaborate on the different polymorphs and the role of calcium in the formation of calcite crystal structures using various calcium sources. ... (above 0.5 M) decrease the efficiency of calcite ...
Calcite, the most stable polymorph of CaCO 3, is the most important and also the most abundant carbonate mineral on Earth 1,2,3.The precipitation of calcite serves as a sink of metals 4,5,6,7 ...
The process consists of grinding and preparation of an aqueous slurry of the ore, adding an effective amount of collector to the slurry (0.1 to about 0.5 pounds per tonne of ore) and …
Calcite occurs in nature either as high-grade (with >75% calcite) or low-grade calcite ores (with <30% calcite). Generally other carbonate, phosphate, silicate, and iron sul-phide minerals are associated with the calcite ores. Gravity and/or magnetic separation and flotation are the beneficiation techniques most commonly applied to calcite ores ...
This paper presents an efficient method of microbial-induced calcite precipitation (MICP) for cementation of sand particles. First, the influence of initial pH value of the culture medium on the growth of bacteria was discussed. ... Suitable grouting speed, concentration of cementation solution and grouting process are beneficial to improve the ...
Benefits of Using Calcite in Water Treatment. To understand the benefits of using calcite in water treatment, delve into its cost-effectiveness, longevity, and sustainable options.. Cost-Effectiveness. Calcite's cost-effectiveness in water treatment processes makes it a great alternative to harsh chemicals. It also helps balance pH levels, reducing the need for …
Flotation is the most efficient method to recover this type of fluorite. Fluorite and calcite contain Ca 2+. During flotation, the physical and chemical properties of the two …
Therefore, it is imperative to find efficient and economic inhibitors to increase the separation efficiency of magnesite and calcite. In the previous research, we studied the influences of sodium hexametaphosphate, sodium tripolyphosphate and dextrin for the flotation behavior of magnesite and calcite under the condition of NaOl as collector.
We have investigated Bayer red mud with a TFe content of 26.86% collected from the Pingguo area of China, and have found that iron is the key metal affecting the extraction of valuable components such as Sc, Ti, and Ga. Based on this, an efficient process of roasting with calcium salt and magnetic separation has been proposed to extract iron from the Bayer red …
It can be seen from Table 6 that the absolute values of adsorption energy of calcite adsorbing tannin and sodium humate at the same time are higher than those of calcite adsorbing tannin alone and ...
As a result, the calcite bed system under the acidified feed at pH 4 and the empty bed contact time (EBCT) at 12.7 min exhibited the most efficient calcite dissolution with …
In summary, calcite formation is a complex process influenced by geological conditions such as temperature, pressure, and fluid composition. Its role in the formation of limestone, marble, and various mineral deposits showcases its significance in understanding Earth's history and the processes that shape the planet's crust.
Microbially induced calcite precipitation (MICP) is a process in which bacteria metabolise urea and calcium chloride to form a natural cement layer of calcium carbonate that binds soil particles ...