Papers by Author: Li Xia Li

Abstract: During practical production, siderite has an influence on flotation efficiency to hematite and magnetite. In flotation system of dodecylamine, this paper studied the flotation properties of single minerals such as magnetite, martite and quartz firstly. On this basis, the influence of siderite to flotation efficiency of martite-quartz and magnetite-quartz mixed ores was discussed. The result shows that siderite will seriously effect on the flotation efficiency of hematite (magnetite)-quartz mixed ores. Increasing the amount of starch will weaken the impact of siderite to some extent.

Abstract: The content of carbonate minerals in Dong Anshan iron ore was increasing in recent years, which deteriorated reverse flotation indices or even resulted in unclear separation between concentrate and tailing. In dodecylamine and sodium oleate systems, reverse flotation tests were undertaken with artificial mixed minerals of martite, quartz and siderite. Based on mineral flotation tests, the effect mechanism of siderite on reverse flotation were investigated in terms of SEM and EDS. Results showed that siderite was weakly depressed by starch, and the adsorption of siderite on hematite and quartz was the main cause for reverse flotation difficulties. In reverse flotation in dodecylamine system, the adverse effect of siderite on reverse flotation could be reduced when the amount of starch increased, and iron minerals and quartz were separated effectively. Therefore, the reverse flotation in dodecylamine system could be considered to realize separating effectively iron minerals and quartz of Donganshan iron ore containing carbonates, but which had high requirements on pH. Other methods were siderite being separated prior to reverse flotation or inventing flotation agents capable of effectively activating or depressing siderite.

Abstract: In this study an attempt has been made to find the suitability of the ceramic waste mud as a possible substitute for conventional concrete. Experiments were carried out to determine the flexural and compressive strengths of concrete and the modulus of elasticity of mortar with various activators. The result indicated that cement could be partly replaced by ceramic waste mud. The strength of concrete verious as the activator changed, so the key to increase the strength of concrete is to find the proper activor.

Abstract: With the purpose that the desulphurization and skimming slag tailings from Ansteel can be used as building materials, the slag tailings were ground to powders with specific surface area 560m²/kg , and then was blended in cement. Strength of slag tailings-blended cement, Physical-mechanical characteristic, frost-resistance and resistance to carbonizing of slag tailings-blended concrete were studied. The experiment results demonstrated that as the amount of tailings increasing, both of the compressive strength and the rupture strength of cement mortar with 3 and 28 curing age decrease gradually, also did the compressive strength of the concrete modules with 28 curing age. The reason why these strengths decreased was also given. The study showed that the optimum amount of slag tailings to be blended was between 10 wt.% to 20wt.%.

Abstract: As an ultra-fine crushing equipment, High-pressure Grinding Roller (HPGR) has unique advantages in crushing refractory ores, owing to its high efficiency and low energy consumption. Low-grade hematite ores from Anshan were crushed by a laboratory CLF-25-10 HPGR with different applied load, roll speed and feed moisture. The different operating factors on the fine crushed products characteristics were investigated and the suitable operating parameters were obtained. The results showed that the product became finer and specific grinding energy increased with applied load increasing, while the capacity did not vary obviously. The capacity was proportional to the roll speed, while product finess and specific grinding energy didn’t change significantly. The moisture of feed was beneficial to coarse particles crushing and went against fine particles crushing. Specific grinding energy increased and capacity increased and then decreased with the increase of feed moisture. It was obtained that applied load of 5.2N/mm2, roll speed of 0.18m/s and feed moisture of 5% were suitable to crushing effect. At these conditions, the percent of -0.074mm production was 21.84%, P80 of product was 2.55mm, specific grinding energy was 1.081Kwh/t and capacity was 1.521t/h.

Abstract: With the purpose that the desulphurized and skimming slag tailings powder from Ansteel replaces part of cement, water requirement of normal consistency, soundness, setting time and strength of cement with desulphurized and skimmed slag tailings was researched respectively in this paper. Results demonstrated that both of the compressive strength and the rupture strength of cement mortar of 3 and 28 concrete age decreased gradually with the amount of tailings increase, and what resulted in strenghth decreased was also investigated, It was shown that suitable amount of tailings to be blended was limited to 30 wt.%.

Abstract: In laboratory, there polymorphs’ nano-calcium carbonates were synthesized through adding on different crystal controlling agents by the bath-type carburizing reagent in the given conditions. When selecting addition J as the crystal controlling agent, lamellar nano-calcium carbonate products with average size about 150×110×15 nm were synthesized. When selecting annexing agent I as the crystal controlling agent, rod nano-calcium carbonates were synthesized, which average grain diameter was 90 nm, average length was 944 nm, and aspect ratio was 10.5. When selecting annexing agent G as the crystal controlling agent, chain nano-calcium carbonate with average grain size 20~30nm, aspect ratio 10~15nm were synthesized.

Abstract: CaCO3 whiskers were synthesized with soluble phosphates by one-step carbonization method, controlling mechanisms were investigated via XRD and FTIR, and it has been indicated that the most stable calcium phosphates in thermodynamics, hydroxyapatite was formed through the reaction of soluble phosphates and Ca(OH)2 in advance before CO2 was introduced, and then [CO32-(OH)] entered the crystal lattices of hydroxyapatite to replace partially [PO43-] to yield B-carbonate hydroxyapatite in the early stage of blowing CO2, which induced aragonite to heterogeneously nucleate as nucleation center and grew into calcium carbonate whiskers by the continuous stack of Ca2+ and CO32-, while other HA selectly adsorbed onto the flanks of CaCO3 to control crystal morphology.

Abstract: Surface modification was conducted on the basic magnesium sulfate whiskers (MSW) using sodium stearate. The modification performance was evaluated by comparing the activation index, oil absorption value, rest angle, and dispersibility in polypropylene (PP) resin prior to and after treatment. It was found that the surface properties of the whiskers were improved by sodium stearate modification. In particular, the improvement in the dispersibility in PP was significant. Surface characterization was conducted using scanning electron microscopy (SEM), thermogravimetric-differential scanning calorimetry (TG-DSC) and fourier transform infrared spectroscopy (FTIR) for the raw and modified whiskers. The results indicated the co-existence of both chemical and physical adsorptions of sodium stearate on the surfaces of MSW.