Effect of sodium salt of naphthalene-formaldehyde polycondensate on ettringite formation

Hekal, Eisa E.; Kishar, Essam A.

doi:10.1016/s0008-8846(99)00110-6

Cited by 31 publications

(23 citation statements)

References 7 publications

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“…The long-chained organic molecules wrap hydrated cement particles and disperse cement particles with electrostatic repulsion [113]. However, increasing amounts of the compound also contributes to reducing the size of ettringite crystals formed during hydration [114], which may negatively affect the expansive properties of SCDA. Naphthalene-based HRWRs also show compatibility to be mixed in conjunction with welan gum [109] and it is essential to determine optimum mix proportions of both VEA and HRWR to produce a slurry sufficiently viscous to resist the water dilution while maintaining its fluidity.…”

Section: Flowability and Injectabilitymentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

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Global energy and material consumption are expected to rise in exponential proportions during the next few decades, generating huge demands for deep earth energy (oil/gas) recovery and mineral processing. Under such circumstances, the continuation of existing methods in rock fragmentation in such applications is questionable due to the proven adverse environmental impacts associated with them. In this regard; the possibility of using more environmentally friendly options as Soundless Chemical Demolition Agents (SCDAs) play a vital role in replacing harmful conventional rock fragmentation techniques for gas; oil and mineral recovery. This study reviews up to date research on soundless cracking demolition agent (SCDA) application on rock fracturing including its limitations and strengths, possible applications in the petroleum industry and the possibility of using existing rock fragmentation models for SCDA-based rock fragmentation; also known as fracking. Though the expansive properties of SCDAs are currently used in some demolition works, the poor usage guidelines available reflect the insufficient research carried out on its material's behavior. SCDA is a cementitious powdery substance with quicklime (CaO) as its primary ingredient that expands upon contact with water; which results in a huge expansive pressure if this CaO hydration reaction occurs in a confined condition. So, the mechanism can be used for rock fragmentation by injecting the SCDA into boreholes of a rock mass; where the resulting expansive pressure is sufficient to create an effective fracture network in the confined rock mass around the borehole. This expansive pressure development, however, dependent on many factors, where formation water content creates a negative influence on this due to required greater degree of hydration under greater water contents and temperature creates a positive influence by accelerating the reaction. Having a precise understanding of the fracture propagation mechanisms when using SCDA is important due to the formation of complex fracture networks in rocks. Several models can be found in the literature based on the tangential and radial stresses acting on a rock mass surrounding an SCDA charged borehole. Those fracture models with quasi-static fracturing mechanism that occurs in Mode I type tensile failure show compatibility with SCDA fracturing mechanisms. The effect of borehole diameter, spacing and the arrangement on expansive pressure generation and corresponding fracture network generation is important in the SCDA fracturing process and effective handling of them would pave the way to creating an optimum fracture network in a targeted rock formation. SCDA has many potential applications in unconventional gas and oil recovery and in-situ mining in mineral processing. However, effective utilization of SCDA in such application needs much extensive research on the performance of SCDA with respect to its potential applications, particularly when considering unique issues arising in using SCDA in different ...

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Section: Flowability and Injectabilitymentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

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“…The action of the first one gives rise to an almost Bingham9s behaviour, whereas SP2 makes the paste behave as a 'shear-thickening' fluid. Based upon previous studies on the adsorption of additives onto the surface of cement particles (Hekal and Kishar, 1999;Kerui et al, 2002;Ouyang et al, 2006;Plank and Hirsch, 2007), this result can be justified assuming that lignosulfonate (SP1) is prone to be adsorbed onto the cement particles even in the presence of polycarboxylate (SP2). In order to confirm this idea, measurements combining SP1 with another polycarboxylated superplasticiser (SP3) were made (CPMX4).…”

Section: Resultsmentioning

confidence: 99%

Experimental study on the influence of two different additives onto the flow behaviour of a fresh cement paste

Rubio-Hernández¹,

Moreno-Lechado²

2011

Advances in Cement Research

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The effects of the concentration of two different additives, lignosulfonate and polycarboxilate, in the rheological parameters of fresh cement pastes were investigated. The geometry of concentric cylinders with a narrow gap was used together with a viscometer. The experimental data shown in the rheograms were fitted with the HerschelBulkley model. As expected, the higher the concentration of the additive, the lower the yield stress and consistency of the material. However, a different trend was observed in the flow index with both additives. This behaviour was explained on the basis of the different nature of the interaction between the particles due to the adsorption of each type of additive. As an example, the influence of additives on the velocity profile shown by the cement paste in a pipeline was determined. A limiting radius was obtained, depending on the value of yield stress.

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“…Furthermore, a decrease in the size of the formed ettringite crystals was observed and as the percentage of the admixture increased, the crystal size decreased (Hekal and Kishar, 1999).…”

Section: Introductionmentioning

confidence: 95%

Influence of some admixtures on the formation of primary and secondary ettringite

Ahmed

Mohammed

2011

Advances in Cement Research

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Different types of admixtures (2% each of superplasticiser, barium nitrate and stearic acid) were added to examine their effect on the hydration reactions of pure tricalcium aluminate (C 3 A) in presence of gypsum (G). The effect of 5% magnesium sulfate solution on the formation of secondary ettringite was examined for different time intervals, 3, 7, 28, 60 and 90 days. The hydration products were investigated using X-ray diffraction, Fourier transform infrared and scanning electron microscopy. The time taken for ettringite formation was determined without admixture and in the presence of admixtures. The results showed that superplasticiser, barium nitrate and stearic acid retard ettringite formation whereas they accelerate the formation of calcium mono-sulfoaluminate hydrate phase and tetracalcium aluminate.

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Effect of sodium salt of naphthalene-formaldehyde polycondensate on ettringite formation

Cited by 31 publications

References 7 publications

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

Experimental study on the influence of two different additives onto the flow behaviour of a fresh cement paste

Influence of some admixtures on the formation of primary and secondary ettringite

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