Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Lime


Studying some of the Geotechnical Properties of Stabilized Iraqi Clayey Soils

Ishraq Khudhair Abass

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 1117-1130

In many road construction projects, if weak soils exist, stabilization and improvement of their properties is necessary. The stabilization process aims at increasing the soil strength and reducing its permeability and compressibility. An experimental program was undertaken to study the effect of engineering properties of kaolin clayey soils ((the kaolin was supplied by the General Company of Geological Survey and Mining which originally obtains from Al-Dewiekhla near Aukashat district in the west of Iraq)) when blended with lime (L) and Silica Fume (SF). A series of laboratory experiments have been implemented for varieties of samples: 2.5%, 5.0%, 7.5% and 10.0% for (Lime) and 2.0%, 4.0% and 6.0% for(Silica Fume). These experiments are: consistency limits test, specific gravity test, compaction test, unconfined compression test and California bearing ratio test. For each test, the optimal quantity of Lime (L) and the optimal percentage of Lime Silica Fume (LSF) combination were determined. The results revealed that: the optimal percentage of LSF combination was attained at a (2.5%L+6.0%SF), which served as control in this study. This optimal percentage: decrease the liquid limit, plasticity index, specific gravity and maximum dry density; and raise the optimum moisture content, unconfined compressive strength and California bearing ratio. These results showed also, that the combination of LSF stabilization at (2.5% L+6.0% SF) is better than the optimal one which achieved by Lime alone: 2.5%L for plasticity index, 10.0%L for specific gravity, maximum dry density and optimum moisture content, 5.0%L for unconfined compression stress and 7.5%forCaliforniabearingratio. All of these results indicated that the engineering properties of clayey soils can be enhanced, by blending Lime and Silica Fume together.

Removal of Heavy Metals Using Chemicals Precipitation

Balasim A. AbiD; Mahmood M. BrbootI; Najah M. Al-ShuwaikI

Engineering and Technology Journal, 2011, Volume 29, Issue 3, Pages 595-612

The single component and multi-component hydroxide precipitation and
adsorption were studied for different heavy metals namely Iron (III), Chromium
(III), Copper (II), Lead (II), Nickel (II), and Cadmium (II) from aqueous solutions.
By using the jar tester Magnesia (MgO) was used as a precipitator at different
doses and compared with other chemicals like lime (CaO) and caustic soda
(NaOH). The treatment involves the addition of either magnesia or lime-water
suspensions (combined with cationic polyelectrolyte, CPE) in various doses, 1.0 –
5.0 g/l for the metal samples to study the effect of varying doses on the treatment
efficiency. The results show that the percent removal of metal ions increases to
about 99 % with increasing the MgO dose to some limits. The optimum values of
MgO doses were found to be 1.5-3.0 g/l. The pH value ranges are 9.5 to 10 with
MgO precipitant and pH of 11.5 to 12 with CaO precipitant. In the jar experiment
the rotation speed, N, 180-200 rpm, (G of 460-480 s-1) of mixing for two minutes
was the most favorable speed of rapid mixing and the slow mixing speed of 15-30
rpm, G of (14-35 s-1), for twenty minutes gave the best results.At the best operating
conditions of the pilot plant, the removal efficiency of metal ions was more than
97% at doses of MgO (1.0-4.0 g/l).

Study Of The Chemical Durability And Hazardous Ionic Leaching Of(Soda-Lime) Glas

Sanaa A. A. Hafad; Abd al khalaq F. Hammod; Huda A. Hussain

Engineering and Technology Journal, 2009, Volume 27, Issue 15, Pages 2751-2759

Huge amounts of glass materials being applied in medical, pharmaceutical
and chemical aqueous solutions; this requires the study of chemical stability of glass at the exposed surfaces with these solutions where the leaching takes place. The leaching of the glass ions will transport these ions to the solutions stored in the glass containers; leading to changes in the chemical composition in the order of part per million that causes hazardous effect with time. The present work investigates the leaching chemical properties of the soda-lime Iraqi glass containers. The effect of the pH of contact solution and
annealing of glass on leaching rates is studied. Ionic leaching shows lower rate with PH of the solutions at the ‘safe zone’: (6>PH>8.5). Annealing increases the leaching rates and reduces of the chemical durability of glass. Increasing annealing time led to further increase the leaching rate. In addition, the increase in the exposed surface area also increases leaching rates.