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Avalon Rare Metals Inc. Message Board

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  • This is an excellent resource; always provide members with useful information about featured companies and their industry- giving a great starting point for research.

  • AAWC announces new agreement to acquire 10-year old IP portfolio. Traders react with a show of interest but can the stock rally past $2?

  • I love seeing what these guys uncover, always something with big potential.

  • Reply to

    60 Min Report Tonight Rare Earths !!!

    by con_man2_2002 Mar 22, 2015 11:13 PM

    Yep. When stay at home mom's start talking Rare Earths in line at the Super Market, you could see a frenzy into non Chineese companies. Good for AVL. LOL.

    Let's get some irrational exuberance.

  • Lets get this ball rolling again. Need to see a dollar.

    Sentiment: Strong Buy

  • Next hurdle is $.40......

    Sentiment: Strong Buy

  • The role of citric acid in the flotation separation of rare earth from the silicates


    No effect of citric acid on the separation of REE from silicates without Al3+.

    The reduction of REE recovery caused by Al3+ was reduced by citric acid.

    Grains reporting to the tailings have less Al on their surface after citric acid addition.

    SiO2 species on the surface of the grains in the tailings with citric acid is diminished.

    Abstract

    The Nechalacho project is the most advanced large heavy rare earth elements (HREE) project outside of China. Open circuit and locked cycle flotation tests along with pilot plant testing of rare earth elements (REE) concentration from the host rocks are accomplished with collectors of alkyl phosphates and the modifier of citric acid. In this study, the function of citric acid in the separation of rare metals against silicates is investigated by a combination of micro-flotation tests and time of flight secondary ion mass spectrometry (ToF-SIMS) surface chemical analysis. It was observed that there was little effect of citric acid on the REE recovery in the micro-flotation tests conditioned with de-ionized water (DIW). To evaluate the flotation response with excess secondary ions in the pulp, micro-flotation tests were performed to look at changes in recovery as a result of adding Al ions and the subsequent presence of citric acid. The results from three micro-flotation tests (DIW, DIW with the addition of 100 mg/L Al and DIW + 100 mg/L Al and 500 g/t citric acid) revealed that the addition of Al ions led to a decrease of REE grade, a lower REE minerals recovery and/or an unexpected promotion of silicates to the concentrate. Citric acid reduced the negative effect generated by the Al ions in the flotation, which was shown by an improvement in REE grade. ToF-SIMS surface analysis of undifferentiated grains from the tests with and without citric acid revealed that grains reporting to the concentrate are doing so in response to collector attachment in combination with having more secondary Al on their surface. Citric acid may partially form aqueous soluble metal–ligand complexes resulting in less Al ions on the grains surface, which were rejected to the tailings. Citric acid also may form chelation competing for adsorption on gangue minerals, resulting in a diminished effectiveness of the activation site.

    Keywords
    Citric acid;
    Rare earth;
    ToF-SIMS;
    Froth flotation

    --------------------------------------------------------------------------------

    1. Introduction

    Previous investigations on the Nechalacho project indicated that the separation of rare earth minerals from oxide and silicate gangue minerals has been successfully carried out by flotation. The following flotation concentration recoveries have been reported: 90% of the zirconium oxide, 69% of the niobium oxide and 63% of the tantalum oxide (Cox et al., 2010). As part of the project, micro-flotation tests were conducted on a feed sample in order to examine factors affecting stream partitioning. SEM–EDX was performed to evaluate variability in grain composition between streams (concentrate and tailings). The results showed that REE containing grains are tentatively identified as monazite, allenite and synchysite. Other minerals examined include zircon and pyrite, along with gangue aluminosilicate phases. The SEM/EDX evaluation indicated that the micro-flotation separation was very successful, as almost no REE grains were identified in the tailings samples (Chehreh Chelgani et al., 2013). However, the reagent scheme used in that micro-flotation was relatively complex and at plant concentration levels. Although reagent signal intensity discrimination on test stream mineral surfaces was observed by the TOF-SIMS analysis, the details of the differences in surface species, particularly related to potential activation (or depression) of the examined mineral phases, is still not clear.

    One of the organic acids used in previous investigations was citric acid, which is a relatively common chelating agent employed in a variety of industries. It forms soluble, weakly bound complexes with metal ions, presumably by means of its carboxylate groups. Liu and Zhang (2000) found that citric acid could effectively remove Ca2+ from chalcopyrite surfaces to increase the selectivity of flotation separation between chalcopyrite and galena using dextrin. Liu and Liu (2004) reported that the role of citric acid in the depression of sulphide minerals seemed to be that of complexation of the copper ions, thus lowering their activity to catalyze the oxidation of thioglycollic acid. Gan et al. (2009) observed that the bitumen-quartz coagulation caused by hydrolysable multivalent metal cations (Fe3+, Mg2+, Ca2+) was reduced or prevented by citric acid. It was summarised that activation of metal ions on flotation of gangue minerals can be reduced through formation of complexes with citric acid. If the mechanism is correct, theoretically EDTA should work for removing multivalent metal ions off gangue mineral surface, thereby reducing their potential for flotation and recovery. A reference reporting on the flotation of dolomite however showed that citric acid functions in a manner different from that of EDTA (Zheng and Smith, 1997). The carboxylate groups of citric acid can chemically adsorb onto the metal active points of the mineral surfaces (dolomite in this reference). It was indicated that citric acid could form chelation complexes with the Ca and Mg atoms on the mineral surface blocking activation sites for collector attachment. There is lots of interest to know how citric acid works as a modifier for flotation separation of rare earth against gangue minerals.

    This research is a systematic study aimed at elucidating the role of citric acid in flotation separation of rare earth minerals from silicates. Micro-flotation testing measured the effect of citric acid in the presence and absence of metal ions (Al3+) in the pulp on the recovery of rare earth. Surface chemical analyses by ToF-SIMS were performed to reveal the relative difference in reagent(s) on grain surfaces from test stream products.

    2. Experimental methodology

    2.1. Minerals and reagents

    A rare earth sample was obtained from Avalon Rare Metals Inc, which had been crushed to a size fraction of −2 mm when received. The micro-flotation feed was prepared in lab as follows: the as received sample was sieved, the coarse fraction (+200 mesh, 75 μm) was processed in a mild steel ball mill. The sieved fine fraction (−200 mesh,

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    Sentiment: Strong Buy

  • just a little oil on the joints

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  • SPAM is on sale at Walmart. Cost? 3 shares of AVL.

  • avl has a booth there,Other rare earths companies attending the conference include:

    Avalon Rare Metals (TSX:AVL) — Booth 2303
    Matamec Explorations (TSXV:MAT) — Booth 3242
    Montero Mining and Exploration (TSXV:MON) — Booth 2647
    Northern Minerals (ASX:NTU) — Booth 2814
    Pele Mountain Resources (TSXV:GEM) — Booth 2302
    Tasman Metals (TSXV:TSM) — Booth 2952

    Sentiment: Strong Buy

  • avl is at such a low price, if you have some change, see what it can do for you. Just take a chance.

    Sentiment: Strong Buy

  • check out the price of the stock at the start of the company. It has lasted all these years.

    Sentiment: Strong Buy

  • feb 2 the chart takes on a new shape. Out with the old in with the new. Year of the Ram. Use indicators. Things change over time.

    Sentiment: Strong Buy

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