Removal of iron from silica sand by leaching with oxalic acid

Taxiarchou, Maria; Panias, Dimitrios; Douni, I.; Paspaliaris, Ioannis; Kontopoulos, A.

doi:10.1016/s0304-386x(97)00015-7

Cited by 108 publications

(61 citation statements)

References 11 publications

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“…Although the pH was not measured or controlled, it was expected that the liquor pH is < pH1 at the oxalic acid concentration range studied (0.19-0.48). Taxiarchou et al [6] found that the maximum iron dissolution of only 40% is within 3 h at temperatures in the range 90-100 0 C. At 0.5M oxalate and all temperatures (25, 60 and 80 0 C) the dissolution of iron was faster at a lower pH in the range pH 1-5 studied. Biological processes for iron dissolution have been evaluated by several researchers based on the use of several micro organisms that were easily sourced and isolated.…”

Section: Introductionmentioning

confidence: 92%

“…Oxalic acid was found to be the most promising because of its acid strength, good comlexing characteristics and high reducing power, compared to other organic acids. Using oxalic acid, the dissolved iron can be precipitated from the leach solution as ferrous oxalate, which can be re-processed to form pure haematite by calcinations [6]. Many researchers have studied the use of oxalic acid to dissolve iron oxide on a laboratory scale [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

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Model for Predictive Analysis of Heat Absorbed by Oxalic Acid Solution Relative to the Solution Temperature during Leaching of Iron Oxide Ore

Nwoye¹,

Nwobodo²,

Nlebedim³

et al. 2009

JMMCE

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Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Model for Predictive Analysis of Heat Absorbed by Oxalic Acid Solution Relative to the Solution Temperature during Leaching of Iron Oxide Ore

Nwoye¹,

Nwobodo²,

Nlebedim³

et al. 2009

JMMCE

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“…In addition, there are recorded efforts to improve iron removal from silica by using Cyclojet or pneumatic flotation cells [15,16]. The last step for iron removal from silica is leaching, and many works have been conducted to investigate iron removal from silica [17][18][19][20][21]. It should be mentioned that some efforts were made to remove iron from relatively low grade silica using different reagents (H 2 SO 4 , HCl, and oxalic acid) in leaching experiments [1,6,22,23].…”

Section: Enrichment Of Silica Used In the Glass Industrymentioning

confidence: 99%

A New Experimental Approach to Improve the Quality of Low Grade Silica; The Combination of Indirect Ultrasound Irradiation with Reverse Flotation and Magnetic Separation

et al. 2016

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Abstract:Removal of iron impurities in silica is one of the most important issues in the glass industry. The most noted impurities are surface coating and staining on silica particles; additionally, some cases of inclusions are observed. The prepared silica sample, for this research work, mostly was in the size range of 106-425 µm. Mineralogical studies indicated the existence of goethite, hematite, limonite and pyrite as the major iron impurities. The poor liberation degree of silica particles from clays encouraged the use of ultrasound irradiation to improve the efficiency of reverse flotation. The head sample contained 96.98% SiO 2 , 0.143% Fe 2 O 3 , 1.52% Al 2 O 3 , and 0.088% TiO 2 ; Fe 2 O 3 had to be reduced to below 0.04%. The reverse flotation tests were carried out with and without indirect ultrasound irradiation. The lowest Fe 2 O 3 grade of the flotation yield was 0.058% and this was achieved using 2000 g/t of C 4 collector with 15 min conditioning at neutral pH. C 4 consisted of Aero 801, Aero 825, oleic acid and sodium oleate at equal dosage. As a result, a flowsheet was developed to include indirect ultrasound irradiation with reverse flotation and two stages of dry high intensity magnetic separation. In conclusion, the best product contained 98.43% SiO 2 , 0.034% Fe 2 O 3 , 0.90% Al 2 O 3 and 0.051% TiO 2 .

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“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The review identified the following cleaning agents as candidates.…”

Section: Approachmentioning

confidence: 99%

Investigation of Alternative Approaches for Cleaning Mott Porous Metal Filters

Poirier

2003

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SummaryThe Department of Energy selected Caustic Side Solvent Extraction (CSSX) as the preferred cesium removal technology for Savannah River Site (SRS) waste. As a pretreatment step for the CSSX flowsheet, the incoming salt solution that contains entrained sludge is contacted with monosodium titanate (MST) to adsorb strontium and select actinides. The resulting slurry is filtered to remove the sludge and MST. Filter fouling occurs during this process. At times, personnel can increase the filtrate rate by backpulsing or scouring. At other times, the filtrate rate drops significantly and only chemical cleaning will restore filter performance. The current baseline technology for filter cleaning uses 0.5 M oxalic acid. The Salt Processing Project (SPP) at SRS, through the Tanks Focus Area, requested an evaluation of other cleaning agents to determine their effectiveness at removing trapped sludge and MST solids compared with the baseline oxalic acid method.A review of the technical literature identified compounds that appear effective at dissolving solid compounds. Consultation with the SPP management team, engineering personnel, and researchers led to a selection of oxalic acid, nitric acid, citric acid, and ascorbic acid for testing. Tests used simulated waste and actual waste as follows. Personnel placed simulated or actual SRS High Level Waste sludge and MST in a beaker. They added the selected cleaning agents, stirred the beakers, and collected supernate samples periodically analyzing for dissolved metals.The conclusions from this work follow.• 0.5 M oxalic acid and 4.0 M nitric acid proved most effective at dissolving iron, aluminum, and titanium. The 0.5 M oxalic acid solution dissolved 23 -44 % of the iron, 11 -41 % of the aluminum, and 98 -100 % of the titanium calculated to be present in the solids used in the tests. The 4 M nitric acid solution dissolved 15 -32 % of the iron, 13 -47 % of the aluminum, and 67 -100% of the titanium calculated to be present in the solids used in the tests. The citric acid solution dissolved 1 % of the iron, 7 % of the aluminum, and 17 % of the titanium. The ascorbic acid solution dissolved 8 % of the iron, 5 % of the aluminum, and 2 % of the titanium.• 0.5 M oxalic acid proved more effective at dissolving iron, titanium, and silicon.• 4 M nitric acid proved more effective at dissolving aluminum.• Decreasing the concentration of oxalic acid or nitric acid decreased the amount of solids dissolved. Decreasing the oxalic acid concentration to 0.25 M reduced the amount of iron (from 23 to 10 %), aluminum (from 15 to 10 %), and titanium (from 100 to 56 %) dissolved. Decreasing the nitric acid concentration from 4 M to 0.5 M decreased the amount of iron (from 18 to 3 %), aluminum (from 19 to 9 %), and titanium (from 89 to 7 %) dissolved.Based on these studies, the SPP should maintain 0.5 M oxalic acid as the baseline cleaning technology for the Salt Waste Processing Facility, and the Alpha Removal Project should use 0.5 M oxalic acid as their baseline cleaning solution.

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Removal of iron from silica sand by leaching with oxalic acid

Cited by 108 publications

References 11 publications

Model for Predictive Analysis of Heat Absorbed by Oxalic Acid Solution Relative to the Solution Temperature during Leaching of Iron Oxide Ore

Model for Predictive Analysis of Heat Absorbed by Oxalic Acid Solution Relative to the Solution Temperature during Leaching of Iron Oxide Ore

A New Experimental Approach to Improve the Quality of Low Grade Silica; The Combination of Indirect Ultrasound Irradiation with Reverse Flotation and Magnetic Separation

Investigation of Alternative Approaches for Cleaning Mott Porous Metal Filters

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