Our chestnut wood to tin mine in Guangxi election refineries, for example. Because the minerals of strontium, barium and tungsten are closely symbiotic with cassiterite and cannot be separated by beneficiation method, a special three-stage reduction smelting process (see Figure 1) is adopted to recover tin as much as possible without causing bismuth, antimony and tungsten to be dispersed. Concentrated in the slag. The slag of the plant is divided into rich slag, lean slag and old slag (the tin slag accumulated for many years). The composition is shown in Table 1.
Table 1 Composition of tin slag in chestnut tin ore refinery / %
Slag name | (Ta,Nb) 2 O 5 | Sn | WO 3 | TiO 2 | Fe | As | Cu |
Rich slag Poor Old slag | 11.7 1.57 1.84 | 4.31 5.18 7.7 | 3.0 6.04 13.12 | 3.6 1.08 | 8.49 7.37 | 0.2 | 0.01 0.39 |
Slag name | Al 2 O 3 | U 3 O 8 | ThO 2 | SiO 2 | Mo | MnO | Ca |
Rich slag Poor Old slag | 5.21 | 0.54 | 0.095 | 23.4 25.8 | 0.714 | 1.4 2.06 | 4.19 8.16 |
Figure 1 The tin tin tin tinning process
The plant handles the treatment of old slag with strontium and strontium concentrates, and the treatment of rich slag and lean slag with samarium, tantalum and tungsten concentrates. Table 2 shows the bismuth tungsten concentrate of the plant and the composition of the slag slag treated with it. The production process is shown in Figure 2.
Table 2 Chestnut tin ore refinery 钽铌 tungsten concentrate and its matching tin slag composition /%
Material name | Ta 2 O 5 | Nb 2 O 5 | WO 3 | Sn |
Thorium tungsten concentrate Tin slag | 7.3 to 9.3 4~6 | 8~9 3 to 4 | 36～41 5.58 | 4.7 to 5.5 5.18 |
Material name | Fe | Si | Ca | S |
Thorium tungsten concentrate Tin slag | ~12 9 to 13 | ～18 13~23 | 0.1 ~4 | 0.05~0.16 ～0.01 |
Figure 2 (1) Process for recovering tantalum tungsten from smelting slag (enrichment of niobium and recovery of tungsten and tin)
Figure 2 (2) Process for recovering tantalum tungsten from smelting slag (recovered by 钽铌 enrichment) [next]
Since the selected antimony content and impurity content of the antimony tungsten concentrate and the tin refining slag do not meet the requirements of antimony concentrate, it is necessary to carry out enrichment treatment to remove some impurities and comprehensively recover tungsten tin. Enrichment operations include: batch grinding, soda roasting, boiled de-tungsten, dilute hydrochloric acid desiliconization, hydrochloric acid to digest Mn, Fe, Sn, Mo, Mg, Ca and other impurities, yielding rich for extraction and separation Collecting things. The operations and indicators of enrichment are as follows:
Enrichment:
De-tungsten:
(1) After the coarse concentrate and slag are dried (the slags larger than 25mm must be broken), mix with soda and charcoal according to the following ratio:
Rich residue: soda: charcoal = 100:25:5
Lean: Soda: Charcoal = 100: (30 ~ 35): (5 ~ 10)
Concentrate: soda: charcoal = 100:40:6
Then, it was dry-milled in a ¢900 mm×2400 mm ball mill, milled to 95% or more to -100 mesh, and added to a rotary kiln for roasting using a screw feeder.
(2) Size of kiln (inner ¢ 460mm) outer ¢ 800mm × 6000mm, firing temperature 850 ~ 900 ℃, time 45min, the production capacity of 1. 8t / d.
(3) The calcined material was discharged into an overflow ball mill (¢900 mm × 1500 mm) for wet grinding.
(4) The ground slurry is placed in a boiling water tank and heated directly with steam. The boiling temperature is 90 ° C, solid: liquid = 1: (2.5 ~ 3), time 1 h.
(5) The de-tungstening efficiency of baking and water immersion is about 56%, and 10% of tin and about 2% of cerium enter the solution.
(6) The boiled slurry is filtered in a vacuum suction filter to recover tungsten from the filtrate; the filter residue is further desiliconized and tin is recovered.
Desilication and removing acid-soluble metal impurities:
(1) The filter residue after de-tungsten also contains a large amount of silicon, and most of it is in the form of Na 2 SiO 4 . Desiliconization is carried out with 7% to 9% hydrochloric acid to convert sodium silicate into silicic acid into the solution. Adding dilute acid at a solid-liquid ratio of 1:6, and filtering immediately after stirring for 3 minutes, so as to prevent the silicic acid molecules from being condensed into a gelatinous form and difficult to filter. The slag production rate during desiliconization is 60% to 70%, and tin is lost to the solution in the process.
(2) In the slag after desiliconization, the grade of strontium increased accordingly: the (Ta, Nb) 2 O 5 in the slag increased from 10.96% to 25.93%; the slag increased from 1.85% to 4.8%. The slag is further subjected to acid extraction to remove acid-soluble impurities such as Fe, Mn, Mo, Mg, Sn, and Ca, so that the hydrazine is further enriched.
(3) 12% to 15% hydrochloric acid for the acid cooking operation. Solid: liquid = 1:6, the temperature is higher than 90 ° C, and stirred for 2 h. Tin enters the solution as SnCl 4 . After filtration, the filtrate is used to recover tin; the filter residue contains (Ta, Nb) 2 O 5 up to 30%, and is dried for recovery.
(4) In the enrichment operation, the recovery rate of ruthenium is 93% to 97%, and the recovery rate of ruthenium in the form of Ta 2 O 5 is 98.5% to 98.9%; the recovery rate of ruthenium in the form of Nb 2 O 5 is 88% ～ 95%.
Production of industrial pure WO 3 :
(1) The boiled solution contains WO 3 20 g/L, and is purified by MgCl 2 to remove clarified filtration of P, As, and Si.
(2) The purified liquid after filtration is heated to 80 to 90 ° C, and a saturated solution of CaCl 2 is added to synthesize artificial white tungsten .
(3) Decomposing white tungsten with hydrochloric acid to form crude tungstic acid, filtering and washing, drying and calcining, then obtaining industrial pure WO 3 powder finished product, the chemical composition (%) is: 99.8wO 3 , 0.052Mo, 0.025As, 0.0006P, 0.002S, 0.080 chlorinated residue, 0.022 times semi-oxide. Loose ratio: 0.574, burning 0.33%. The recovery rate of tungsten is 78.5%.
Production of chemically pure WO 3 :
(1) The solution after boiling (WO 3 60-70 g/L, As 0.12 to 0.46 g/L, Mo 0.0056 to 0.022 g/L, NaOH 8 to 24 g/L) is separated by an ion exchange process.
(2) Adsorption of tungsten with strong alkaline 717 anion exchange resin requires sodium tungstate solution containing WO 3 15-20 g/L and alkali 2-6 g/L, so the solution is diluted to the above concentration and then passed through ¢800 mm×3000 mm. The exchange column is ion exchanged.
(3) The resin after the exchange capacity was saturated was desorbed with a solution of 6 mol/L NH 4 Cl + 2 mol/L NH 4 OH. The desorbed ammonium tungstate solution contains WO 3 170-200 g/L. The exchange residue (disposal) contains WO 3 <0.2 g/L and 90% or more of phosphorus which is not adsorbed, 80% or more of arsenic , and 95% or more of silicon.
(4) The concentrated ammonium tungstate solution is obtained by evaporation crystallization to obtain chemically pure ammonium paratungstate or re-calcined into a chemically pure WO 3 product (calcining furnace power 150 kw). The total recovery from sodium tungstate to WO 3 product was 92%.
Recycling tin:
(1) hydrochloric acid tin-containing filtrate was boiled 12 ~ 18g / L, so that the reduction with scrap iron as reducing Sn 4 Sn 2+, for ease of electrodeposition. The amount of iron filings is 20 to 25 g/L. After standing at room temperature for 48 h, it can be used for electrowinning when the supernatant is dark green or light blue.
(2) The electrowinning condition of the SnCl 2 solution is: current density 10A/m 2 , pole pitch 94mm, cell voltage 0.6~2V.
(3) The cathode component (%) produced by the cathode is 75 to 85 Sn, 0.7 to 2 Ca, 0.3 to 1.5 Fe, and 0.01 to 0.04 Bi, and is sent to refining.
(4) Tin recovery rate of reduction and electrowinning process: 94%.
The operations and indicators for the recovery of plutonium are as follows:
Decomposition and extraction of enriched materials:
(1) The enrichment component (%) produced by the enrichment operation is: 41. 48 (Ta, Nb) 2 O 5 , 1.5 to 2.5 WO 3 , 7 to 9 Sn, about 3 Fe, about 1 Si, 0.3 to 0.5 Mg, about 0.008 Ã…, was decomposed with hydrofluoric acid.
(2) The decomposition operation was carried out in a ¢1400 mm × 1400 mm, graphite- lined decomposition tank, and 15 mol1/L hydrofluoric acid was added, solid: liquid = 1:2.5, and the acidity of the slurry was adjusted with 2.75 to 3.0 mol/L H 2 SO 4 . The decomposition reaction is:
Ta 2 O 5 +14HF=2H 2 TaF 7 +5H 2 O
Nb 2 O 5 +14HF=2H 2 NbF 7 +5H 2 O
(3) The decomposed pulp is directly introduced into the extraction tank and extracted with a sec-octanol-HF-H 2 SO 4 system.
(4) The size of the slurry extraction mixing chamber is: 180mm × 180mm × 410mm; the sinking chamber is: 180mm × 545mm × 410mm, and the produced loaded organic phase enters the cleaning tank, first using 3.5mol / L H 2 SO 3 + 2mol / LHF The impurities were washed back, and the ruthenium was back extracted with 1 mol/L of H 2 SO 4 , and finally the ruthenium was back extracted with pure water. The various solution components of the stripping are shown in Table 3. The approximate organic component (g/L) of the supported organic phase produced is: 150-180 (Ta+Nb) 2 O 5 , about 2WO 3 , about 2.5 Sn, a certain amount of HF + H 2 SO 4 . The residual phase is a slurry with a solid containing (Ta+Nb) 2 O 5 ≤ 1% and a residual liquid containing (Ta + Nb) 2 O 5 ≤ 0.5 g / L. The extraction recovery of hydrazine was 99%.
Table 3 Various liquid components obtained by stripping during the extraction process
Liquid name | Ta 2 O 5 /g·L -1 | Nb 2 O 5 /g·L -1 | HF+H2SO4 |
铌 liquid 钽 liquid Residual liquid Cyclic organic phase | <0.5 50-70 <0.5 2 to 5 | 100~150 <0.1 <0.5 1 | A certain amount of A certain amount of PH≤4 |
(5) Three tank-type extraction tanks are used for pickling, raking, and smashing operations. The first two specifications are 105 mm x 105 rnm x 280 mm, and the latter are 130 mm x 130 mm x 370 mm.
(6) After extracting the slurry residue after the mash, after solid-liquid separation, the residue is buried, and the residual liquid is diluted and discharged. The octanol is returned for use.
(7) The content of octanol in the organic phase has an effect on the extraction and phase separation of hydrazine. When the content of octanol is above 85%, high purity bismuth and sharp compounds can be obtained. The octanol has low water solubility and low cost, but has a high viscosity, and emulsification often occurs during stripping, making operation difficult to control.
Recovery of niobium oxide:
(1) The qualified sputum or sputum which is back-extracted, neutralized to pH=9 by liquid ammonia, and after being washed, filtered and dried, Ta (OH) 5 or Nb (OH) 5 product is produced, and then Calcination yields a Ta 2 O 5 or Nb 2 O 5 product. The recovery (%) was: Ta 2 O 5 86.93; Nb 2 O 5 87.93.
(2) The composition of cerium oxide and cerium oxide is shown in Table 4.
Table 4 Composition of cerium oxide and cerium oxide /%
name | Ta 2 O 5 | Nb 2 O 5 | WO 3 | Fe | Ti | Ni 2 O 3 | Mo |
Yttrium oxide Yttrium oxide | 99.84 0.8 | 0.07 98.72 | 0.057 | 0.005 | 0.003 | 0.02 | 0.003 |
Pb 0.003 | As 0.003 | Sb 0.003 | Bi 2 O 5 0.006 | Sn 0.012 | |||
name | Mn | Al | S | P | SiO 2 | Burning down | |
Yttrium oxide Yttrium oxide | 0.003 | 0.006 | 0.0026 0.004 | 0.005 0.007 | <0.005 0.037 | 0.94 0.18 |
(3) The sputum is acidified, heated, and added to KCI, and the following reactions occur:
H 2 TaF 7 +2KCl=K 2 TaF 7 ↓+2HC1
The crystals were cooled to obtain a white needle-like potassium fluorite (K 2 TaF 7 ) crystal. The crystallization ratio was 88%.
(4) The crystallization mother liquor contains (Ta+Nb) 2 O 5 4g/L, which is recovered by ammonia precipitation. The obtained precipitate contains Ta 2 O 5 ≈ 75%, Nb 2 O 5 = 2% ～ 3%, and is sent to the decomposition process again. Decomposition and extraction.
Hydraulic Ball Valve,Three Way Ball Valve,High Pressure Steel Hydraulic Ball Valve,Full Port Three-Way Ball Valve
Huaian Hy-waloil Machinery Co.,Ltd , https://www.hywaloil.com