Light Magnesium Carbonate Research Articles

Mechanical and thermal characterization of condom industry waste reinforced natural rubber composites - Circular economy approach

Condom industry waste mainly consists of light magnesium carbonate (LMC), which is extensively used as a finishing powder during the final stages of condom production. This LMC waste (LW) is usually disposed of as a landfill, causing an increase in the hardness of water. LW generated in HLL Lifecare Limited, India, was procured, characterized by analytical techniques, and reutilized in natural rubber (NR) as a reinforcing filler. The prepared composites were subjected to rheological, mechanical, thermal and sorption characterizations. In comparison to NR neat, the composite with 3 phr (parts per hundred of rubber) LW showed a rise in tensile strength, tear strength, and modulus at 300% elongation by 22%, 20%, and 28%, respectively. A remarkable decrease in abrasion loss is also evidenced. The activation energy (Ea) for degradation, calculated by the Coats-Redfern (CR) method, showed 10 kJmol-1 increase for composite with 3 phr LW, proving its better thermal stability. It also exhibited higher solvent uptake resistance, as established by sorption experiments. The superior properties of this composite have been attributed to the uniform LW distribution and ameliorated NR-LW interaction. Hence, the prepared composites find considerable potential in manufacturing industrial NR components accomplishing a circular economy.

Development and In Vitro Evaluation of Oral Capsules from Antiaris: A Convenient Substitute for Peripheral Neuropathy.

Antiaris is a monoherbal decoction produced by the Centre for Plant Medicine Research (CPMR), Mampong-Akuapem, Ghana. It is prepared from the stem bark of Antiaris africana Engl. (Moraceae), prescribed, and dispensed to patients for the management of nervous disorders. This current formulation presents notable challenges in patients' adherence to treatment regimen due to its bulkiness and bitterness. These challenges have resulted in a decrease in therapeutic outcome. This study sought to transform Antiaris into oral capsules to mask its bitter taste and reduce bulkiness of the product to improve patients' convenience. In this study, four (4) conventional release capsule formulations were successfully prepared from the decoction via wet granulation using corn starch, lactose, light magnesium carbonate (LMC), and microcrystalline cellulose (MCC) and labelled A01, A02, A03, and A04 respectively. The drug-excipient compatibility studies on A01, A02, A03, and A04 were investigated using Fourier transform infrared (FTIR) spectroscopy. The flow properties of the granules as well as the quality assessment of the formulations such as dissolution, disintegration, uniformity of weight, and assay tests were evaluated using pharmacopoeial and nonpharmacopoeial methods. Appropriate models were used to investigate the difference factor (f1) and similarity factor (f2) of the dissolution profiles of the formulations and Antiaris. From the study, all formulated granules had excellent flow properties with Carr's index from 7.83 to 9.56%, Hausner's ratio from 1.09 to 1.10, and angle of repose from 25.13 to 27.87°. Drug-excipient compatibility studies demonstrated no interaction between extract and used excipients. All formulations passed the uniformity of weight, disintegration, assay, and dissolution tests. Formulation A02 had the highest dissolution efficiency of 100.12%, while A03 recorded the least value of 97.22% in the 1 h dissolution studies. A comparison of their various dissolution profiles, respectively, to that of its decoction demonstrated their similarity, since, in all comparisons, f2 < 15 and f1 > 50. This implies that, any of these four formulations could be a good substitute for Antiaris.

Sintering and characterization of aluminum titanate ceramics with enhanced thermomechanical properties

Aluminum titanate (Al2TiO5) was synthesized from Al2O3-TiO2 system by solid-phase reaction with additives of light magnesium carbonate and SiO2, incorporating with silicon carbide (SiC) particle. The influence of additives on the phase composition, microstructure configuration, sintering, and thermomechanical properties of the developed materials was investigated. The experimental results illustrated that the utilization of additives with applicable contents was conducive to the development of complex microstructures. The microstructures characterized by microcracks matrix together with interlocked grains were identified. The samples incorporating SiC and SiO2 simultaneously displayed exceptional densification properties and microstructure as a result of a SiO2 liquid phase accelerating SiC oxidation. Meanwhile, high flexural strength (41.51 MPa) and low thermal expansion coefficient of 0.485 × 10−6 K−1 (RT-1000 °C) were detected, encouraging refractory applications with high thermomechanical solicitations.

Indirect mineral carbonation of titanium-bearing blast furnace slag coupled with recovery of TiO 2 and Al 2 O 3

Abstract Large quantities of CO2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO2 emission reduction and comprehensive utilization of the solid waste. This paper describes a novel route for indirect mineral carbonation of titanium-bearing blast furnace (TBBF) slag, in which the TBBF slag is roasted with recyclable (NH4)2SO4 (AS) at low temperatures and converted into the sulphates of various valuable metals, including calcium, magnesium, aluminium and titanium. High value added Ti- and Al-rich products can be obtained through stepwise precipitation of the leaching solution from the roasted slag. The NH3 produced during the roasting is used to capture CO2 from flue gases. The NH4HCO3 and (NH4)2CO3 thus obtained are used to carbonate the CaSO4-containing leaching residue and MgSO4-rich leaching solution, respectively. In this study, the process parameters and efficiency for the roasting, carbonation and Ti and Al recovery were investigated in detail. The results showed that the sulfation ratios of calcium, magnesium, titanium and aluminium reached 92.6%, 87% and 84.4%, respectively, after roasting at an AS-to-TBBF slag mass ratio of 2:1 and 350 °C for 2 h. The leaching solution was subjected to hydrolysis at 102 °C for 4 h with a Ti hydrolysis ratio of 95.7%and the purity of TiO2 in the calcined hydrolysate reached 98 wt%. 99.7% of aluminium in the Ti-depleted leaching solution was precipitated by using NH3. The carbonation products of Ca and Mg were CaCO3 and (NH4)2Mg(CO3)2·4H2O, respectively. The latter can be decomposed into MgCO3 at 100–200 °C with simultaneous recovery of the NH3 for reuse. In this process, approximately 82.1% of Ca and 84.2% of Mg in the TBBF slag were transformed into stable carbonates and the total CO2 sequestration capacity per ton of TBBF slag reached up to 239.7 kg. The TiO2 obtained can be used directly as an end product, while the Al-rich precipitate and the two carbonation products can act, respectively, as raw materials for electrolytic aluminium, cement and light magnesium carbonate production for the replacement of natural resources.

Indirect mineral carbonation of blast furnace slag with (NH4)2SO4 as a recyclable extractant

Large quantities of CO2 and blast furnace slag are discharged in the iron and steel industry. Mineral carbonation of blast furnace slag can offer substantial CO2 emission reduction and comprehensive utilisation of the solid waste. In this study, a recyclable extractant, (NH4)2SO4, was used to extract calcium and magnesium from blast furnace slag (main phases of gehlenite and akermanite) by using low-temperature roasting to fix CO2 through aqueous carbonation. The process parameters and efficiency of the roasting extraction, mineralisation, and Al recovery were investigated in detail. The results showed that the extractions of Ca, Mg, and Al can reach almost 100% at an (NH4)2SO4-to-slag mass ratio of 3:1 and at 370 °C in 1 h. Adjusting the pH value of the leaching solution of the roasted slag to 5.5 with the NH3 released during the roasting resulted in 99% Al precipitation, while co-precipitation of Mg was lower than 2%. The Mg-rich leachate after the depletion of Al and the leaching residue (main phases of CaSO4 and SiO2) were carbonated using (NH4)2CO3 and NH4HCO3 solutions, respectively, under mild conditions. Approximately 99% of Ca and 89% of Mg in the blast furnace slag were converted into CaCO3 and (NH4)2Mg(CO3)2•4H2O, respectively. The latter can be selectively decomposed to magnesium carbonate at 100–200 °C to recover the NH3 for reuse. In the present route, the total CO2 sequestration capacity per tonne of blast furnace slag reached up to 316 kg, and 313 kg of Al-rich precipitate, 1000 kg of carbonated product containing CaCO3 and SiO2, and 304 kg of carbonated product containing calcium carbonate and magnesium carbonate were recovered simultaneously. These products can be used, respectively, as raw materials for the production of electrolytic aluminium, cement, and light magnesium carbonate to replace natural resources.

A hazard and operability analysis method for the prevention of misoperations in the production of light magnesium carbonate

A method of preventing misoperations in the process of producing light magnesium carbonate with a rotating packed bed (RPB) is proposed in this paper. The main problem in this process is that the carbonization reaction and the purity of light magnesium carbonate are easily affected by misoperations, which result in the waste of materials and energy, low quality of the product, and so on. A hazard and operability analysis method was used to analyze misoperations in the process of producing light magnesium carbonate. It was found that the situations caused by misoperations, such as the operation step neglect and inversion, can be detected and arranged properly by a misoperation hazard and operability (MO-HAZOP) analysis program according to the probability of the misoperation occurrence. Based on the analysis results, the measures in terms of full automatic mechanism, programmed control system, interlock mechanism can be adopted to reduce and prevent misoperations and to maintain the normal production. The use of this method in the production of light magnesium carbonate has shown that the occurrences of misoperations and accidents were reduced drastically, and the security and protection system in this process was improved considerably.

Study of Carbonizing Processes for Sintered Dolomite

It is the easy and widely used way to make light calcium carbonate and magnesium carbonate from dolomite by carbonizing process. During this process, the dolomite is calcined at different temperature, from 700°C to 950°C to get the mixture including either calcium carbonate and magnesia or calcia and magnesia. Then the mixture is blended with water in different temperature from room temperature to 80°C. As a result, it is supposed to get calcium hydroxide and magnesium hydroxide, but XRD analysis reveals that it is not accord with the theory. Magnesium hydroxide can not be obtained during this reaction. After the carbonization process, the calcium carbonate and a kind of mixture which is composed with different crystal phase of Mg5(CO3)4(OH)2[H2O]4 have been produced, instead of magnesium carbonate. The magnesia is gotten when the mixture is calcined at 450~750°C.

Solution calorimetry as a tool to study the neutralising capacity of magnesium trisilicate mixture BP and its components

Magnesium trisilicate mixture BP, a liquid antacid, contains three active components; magnesium trisilicate BP (MT) (5% (w/v)), light magnesium carbonate BP (LMC) (5% (w/v)) and sodium bicarbonate BP (SB) (5% (w/v)). The role of each component in the mixture is not well understood although each contributes to the overall acid neutralising capacity (ANC) of the product, the standard measure by which antacid performance is rated. Previous work has suggested that the inclusion of magnesium trisilicate BP in the mixture is unwarranted [Int. J. Pharm., 29 (1986) 253], because of its extremely slow reaction with hydrochloric acid. In light of these observations, there is a need to study the basic mechanisms of neutralisation of the components of the mixture. Since the heat change associated with simple mono-protic acid–base neutralisation is approximately −57 kJ mol −1 [Chemistry Data Book, John Murray, London, 1982], calorimetry may be used to study the reactions. In this work, the relative contributions to the ANC of the product of each component were measured using solution calorimetry. It was found that light magnesium carbonate BP contributed most to the overall ANC of the product, sodium bicarbonate BP the least. Magnesium trisilicate BP was found to neutralise acid over an extended time period, and contributed most to the duration of action of the dose. Moreover, it appears that light magnesium carbonate BP and magnesium trisilicate BP in combination exhibit a greater than expected ANC, showing positive synergy.

Interaction of digoxin with activated dimethicone and other antacid constituents

A study was made of the effect of activated dimethicone on the absorption of digoxin in relation to other commonly used antacid constituents using an in vitro experimental model. Dimethicone was found not to affect the absorption of digoxin in relation to aluminium hydroxide, bismuth carbonate, light magnesium carbonate and magnesium trisilicate whose effects on the absorption of digoxin were in agreement with values reported in the literature.

Further studies of the major lipoproteins made possible by the adsorption to magnesium compounds

The adsorption techniques for removing the β-lipoprotein and both the α-lipoprotein and the β-lipoprotein from sera have been examined. New findings include: 1.A preβ-lipoprotein: β-lipoprotein cholesterol ratio greater than 0.4 in the Frederickson types III, IV and V; 2.A good correlation between the cholesterol and the triglyceride in the preβ-lipoprotein and a poor correlation in the β-lipoprotein; 3.The characteristics of a ‘midβ-lipoprotein’ which moves between the β-lipoprotein and the preβ-lipoprotein during electrophoresis in agar. It is not adsorbed by light magnesium carbonate yet is adsorbed by the mixture of light magnesium carbonate and magnesium trisilicate, can be found in normal sera, appears increased in Frederickson's type lib phenotype, apparently still has α-lipoprotein antigenic determinants, and seems to bind very little cholesterol; 4.Estimations for corrections that may be applied to allow for the α-lipoprotein cholesterol that is removed by the adsorption with light magnesium carbonate. Approximately 38-40% of the α-lipoprotein cholesterol is removed, yet the carrier protein appears relatively resistant to adsorption even by the magnesium carbonate and trisilicate. The removal of β-lipoprotein cholesterol causes the β-lipoprotein cholesterol to be read too high unless corrections are applied. The adsorption techniques for removing the β-lipoprotein and both the α-lipoprotein and the β-lipoprotein from sera have been examined. New findings include: 1.A preβ-lipoprotein: β-lipoprotein cholesterol ratio greater than 0.4 in the Frederickson types III, IV and V; 2.A good correlation between the cholesterol and the triglyceride in the preβ-lipoprotein and a poor correlation in the β-lipoprotein; 3.The characteristics of a ‘midβ-lipoprotein’ which moves between the β-lipoprotein and the preβ-lipoprotein during electrophoresis in agar. It is not adsorbed by light magnesium carbonate yet is adsorbed by the mixture of light magnesium carbonate and magnesium trisilicate, can be found in normal sera, appears increased in Frederickson's type lib phenotype, apparently still has α-lipoprotein antigenic determinants, and seems to bind very little cholesterol; 4.Estimations for corrections that may be applied to allow for the α-lipoprotein cholesterol that is removed by the adsorption with light magnesium carbonate. Approximately 38-40% of the α-lipoprotein cholesterol is removed, yet the carrier protein appears relatively resistant to adsorption even by the magnesium carbonate and trisilicate. The removal of β-lipoprotein cholesterol causes the β-lipoprotein cholesterol to be read too high unless corrections are applied.

COMPARISON OF LIGHT MAGNESIUM CARBONATE AND AMBERLITE SPONGE ADSORBANTS IN THE MEASUREMENT OF THE LATENT IRON-BINDING CAPACITY OF SERUM.

COMPARISON OF LIGHT MAGNESIUM CARBONATE AND AMBERLITE SPONGE ADSORBANTS IN THE MEASUREMENT OF THE LATENT IRON-BINDING CAPACITY OF SERUM.

Studies in hard rubber reaction. Part IV. Effect of fillers

AbstractThe effects of the different fillers i.e., china clay, light magnesium carbonate, Pliolite S6E, and ebonite dust, on the exothermic hard rubber reaction has been studied with the help of differential thermal analysis. The data for heat evolution show some unexpected features in that china clay, a more or less inert filler, lowers heat evolution. The behavior of magnesium carbonate also can not be fully explained. Attempts have been made to explain the data for Pliolite S6E and ebonite dust on the basis of their composition and effects of the individual components on heat of reaction. The differences in initiation temperature and slope values have been explained.

The Preparation and Evaluation of Tangerine Peel Tincture and Tangerine Syrup

A tangerine peel tincture was prepared by maceration of the whole peel from the fresh fruit. In the determination of the oil content of the tinctures, an adaption of the A. O. A. C. precipitation method appeared to have a greater general accuracy than the polarization method. A tangerine syrup was prepared from the tincture, using light magnesium carbonate as the filtering agent. Organoleptic tests indicated that tangerine syrup compared favorably in taste preference with five other vehicles which had ranked high in taste preference tests conducted by other workers. Tangerine syrup also appeared to have a high value in disguising the salty taste of ammonium chloride and a mediocre value in disguising the bitter taste of quinine hydrochloride.

Alcoholic Potash Extraction of Vulcanized Rubber

Abstract In the analysis of vulcanized rubber, the estimation of matter extractable by alcoholic potash solution has long been applied, chiefly as a means of detecting and estimating factice. The test was originally made by weighing the rubber before and after boiling with potash solution, the loss in weight being taken as representing the factice content (cf. Weber, The Chemistry of India Rubber, London, 1919, page 245). Though this method has now been generally superseded by that in which the extract is acidified and the resulting fatty acids are extracted with ether and weighed, the older “loss in weight” method is still prescribed in some specifications for rubber goods. It has long been recognized that the loss in weight is not an accurate measure of the factice content for the following reasons: (1) it is difficult to remove all the potash from the extracted rubber before weighing it (cf. Henriques, Chem.-Ztg. 18, 411(1894)), and (2) the potash extracts part of some mineral compounding ingredients, such as zinc oxide, litharge, and antimony sulfide (cf. Ditmar, Die Analyse des Kautschuks, Vienna, 1909, page 205). It has been found that another possible source of serious errors in the “loss in weight” method is the action of the potash on light magnesium carbonate. If magnesium carbonate is boiled with alcoholic potash solution, it loses a considerable amount of its combined carbon dioxide and/or water. Thus in an experiment where 0.3 gram of the carbonate was boiled for 6 hours with 60 cc. of potash solution (KOH 5 g., water 5 cc., absolute alcohol 100 cc.), and then washed with alcohol, dried in vacuo and weighed, it was found to have lost 29.4 per cent of its weight. By igniting the residue to magnesium oxide, it was shown that the potash had not dissolved out any magnesium compounds, so that the loss in weight must be attributed entirely to loss of carbon dioxide and/or water.

The Influence of Glue on the Reinforcing Effect of Light Magnesium Carbonate in Rubber.

The Influence of Glue on the Reinforcing Effect of Light Magnesium Carbonate in Rubber.

Some Physical Properties of Rubber Compounded with Light Magnesium Carbonate

Some Physical Properties of Rubber Compounded with Light Magnesium Carbonate