REGENERATION OF ALKALI LEACHING SOLUTION THROUGH PHOSPHATE PRECIPITATION USING CALCIUM HYDROXIDE

AbstractIn order to extract molybdenum (Mo) from alkali leaching solution of low-grade Mo concentrate, static and dynamic ion exchange experiments were performed. The static experiments results indicated that the adsorption capacity of D201 resins reached 93.50% at pH 3.5, while the adsorption capacity of D314 resins was 95.47%. Therefore, D314 resin was adopted for further experiments. The dynamic experiments results indicated that the adsorption capacity of Mo reached 96.77% when the flow rate of leaching solution was 1 ml/min. The loaded resin could be desorbed by 10% ammonia solution. In consequence, the maximum concentration of Mo in eluate was 122 g/l. In the precipitation process, the Mo recovery reached 97.81%, and the obtained Mo oxide products met the requirement of YMo 55 national standard in GB/T24482-2009 and Grade A standard of ASTM A146-04 (2014).

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Arsenic Recovery Technology from Compound Alkali Leaching Solution of Phosphoric Acid Waste Arsenic Residue

Hans Journal of Chemical Engineering and Technology ◽

10.12677/hjcet.2020.102017 ◽

2020 ◽

Vol 10 (02) ◽

pp. 119-126

Author(s):

念英苏

Keyword(s):

Phosphoric Acid ◽

Alkali Leaching ◽

Leaching Solution ◽

Acid Waste

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Recovery of Molybdenum and Rhenium Using Selective Precipitation Method from Molybdenite Roasting Dust in Alkali Leaching Solution

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.m2012209 ◽

2012 ◽

Vol 53 (11) ◽

pp. 2038-2042 ◽

Cited By ~ 11

Author(s):

Sung-Ho Joo ◽

Young-Uk Kim ◽

Jin-Gu Kang ◽

Ho-Sung Yoon ◽

Dong-Su Kim ◽

...

Keyword(s):

Precipitation Method ◽

Selective Precipitation ◽

Alkali Leaching ◽

Leaching Solution

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Alkali Release from Aggregates in Long-Service Concrete Structures: Laboratory Test Evaluation and ASR Prediction

Materials ◽

10.3390/ma11081393 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1393 ◽

Cited By ~ 2

Author(s):

Mario Berra ◽

Teresa Mangialardi ◽

Antonio Paolini

Keyword(s):

Calcium Hydroxide ◽

Concrete Structures ◽

Weight Ratio ◽

Standard Test ◽

Test Method ◽

Test Duration ◽

Alkali Extraction ◽

Proposed Model ◽

Leaching Solution

This paper proposes a simple model for predicting the development of deleterious expansion from alkali-silica reaction (ASR) in long-service concrete structures. This model is based on some composition and reactivity parameters related to ASR, including the long-term alkali contribution by aggregates to concrete structures. This alkali contribution was estimated by means of a laboratory extraction test, appositely developed in this study in order to maximize the alkali extraction within relatively short testing times and with low leaching solution/aggregate ratios. The proposed test is a modification of the Italian Standard test method UNI 11417-2 (Ente Nazionale Italiano di Normazione) and it consists of subjecting an aggregate sample to leaching with saturated calcium hydroxide solution in a laboratory autoclave at 105 °C. Nine natural ASR-susceptible aggregates (seven sands and two coarse aggregates) were tested and the following optimized test conditions were found: leaching solution/aggregate weight ratio = 0.6; solid calcium hydroxide/aggregate weight ratio = 0.05; test duration = 120 h. The results of the optimized alkali extraction tests were used in the proposed model for predicting the potential development of long-term ASR expansion in concrete dams. ASR predictions congruent with both the field experience and the ASR prevention criteria recommended by European Committee for Standardization Technical Report CEN/TR 16349:2012 were found, thus indicating the suitability of the proposed model.

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