Chinese Ore Research Articles

Improving Extraction of Chinese Open Relations Using Pre-trained Language Model and Knowledge Enhancement

ABSTRACT Open Relation Extraction (ORE) is a task of extracting semantic relations from a text document. Current ORE systems have significantly improved their efficiency in obtaining Chinese relations, when compared with conventional systems which heavily depend on feature engineering or syntactic parsing. However, the ORE systems do not use robust neural networks such as pre-trained language models to take advantage of large-scale unstructured data effectively. In respons to this issue, a new system entitled Chinese Open Relation Extraction with Knowledge Enhancement (CORE-KE) is presented in this paper. The CORE-KE system employs a pre-trained language model (with the support of a Bidirectional Long Short-Term Memory (BiLSTM) layer and a Masked Conditional Random Field (Masked CRF) layer) on unstructured data in order to improve Chinese open relation extraction. Entity descriptions in Wikidata and additional knowledge (in terms of triple facts) extracted from Chinese ORE datasets are used to fine-tune the pre-trained language model. In addition, syntactic features are further adopted in the training stage of the CORE-KE system for knowledge enhancement. Experimental results of the CORE-KE system on two large-scale datasets of open Chinese entities and relations demonstrate that the CORE-KE system is superior to other ORE systems. The F1-scores of the CORE-KE system on the two datasets have given a relative improvement of 20.1% and 1.3%, when compared with benchmark ORE systems, respectively. The source code is available at https://github.com/cjwen15/CORE-KE.

Ruizhongite, (Ag2☐)Pb3Ge2S8, a thiogermanate mineral from the Wusihe Pb-Zn deposit, Sichuan Province, Southwest China

Abstract Ruizhongite (IMA2022-066), (Ag2☐)Pb3Ge2S8, is a thiogermanate of economic importance discovered in the Wusihe Pb-Zn deposit in Sichuan Province, southwestern China. This mineral occurs as anhedral grains 1–10 μm in size. It is gray and opaque, with a metallic luster and black streak, closely associated with galena and pyrite in a sphalerite matrix. Under reflected light, it displays a greenish-gray color without internal reflection. Its reflectance values in air (R %) based on SiC as the reference material are 30.5, 32.2, 34, and 34.1 for corresponding wavelengths of 650, 589, 470, and 546 nm, respectively. According to the average of 18 electron microprobe analyses, Pb (57.37 wt%), S (21.39 wt%), Ge (11.53 wt%), Ag (7.34 wt%), Zn (1.57 wt%), and Fe (0.27 wt%) constitute 99.46 wt% of ruizhongite. The empirical formula based on the 8 S apfu is (Ag0.82Pb0.32Zn0.28Fe0.06)Σ1.48Pb3Ge1.9S8, and (Ag2☐)Pb3Ge2S8 is its ideal formula. Ruizhongite displays a cubic structure, space group I43d (#220), with the unit-cell parameters a = 14.0559(2), V = 2777.00(7), Z = 8, and the calculated density is 5.706 g/cm3. The strongest powder X-ray diffraction lines [d in Å (I) (hkl)] are 3.755 (100) (123), 3.511 (76) (004), 2.992 (73) (233), 2.574 (21) (125), 2.482 (79) (044), 2.276 (46) (235), 1.784 (39) (237), and 2.075 (24) (136). The structure of ruizhongite was determined using single-crystal XRD and was refined to an R1 of 0.0323 for all 2594 (474 unique) reflections. The structure comprises a non-centrosymmetric arrangement of [GeS4]4− tetrahedra, forming two interstice sites: fully occupied Pb1 and partially occupied Ag1, aligned in the directions of a-, b-, and c-axes. Ruizhongite was named in honor of Ruizhong Hu (1958), an eminent Chinese ore geochemist. The discovery of ruizhongite has significant implications for the occurrence and enrichment mechanism of Ge in sphalerite and other metallic minerals.

Sources of atmospheric lead (Pb) after quarter century of phasing out of leaded gasoline in Bangkok, Thailand

After global phasing out of leaded gasoline, anthropogenic sources of atmospheric lead (Pb) are dominated by coal combustion emissions, high-temperature metallurgical processes, and vehicle exhausts. Thailand was one of the first countries in Southeast Asia to completely phase out leaded gasoline by the year 1994. This study investigates the sources of atmospheric Pb in Thai aerosols, a quarter-century after phasing out of leaded gasoline using a multiproxy approach, Pb isotopes in conjunction with trace metal composition of PM2.5. Aerosol samples were collected for 1 year from January 2018 to April 2019 from Bangkok and Chonburi to understand the influence of seasonal variation on aerosol chemistry. Bangkok is the only megacity in Thailand and notorious for traffic congestion and Chonburi is a coastal town, 80 km southeast of Bangkok where the inter monsoon winds make landfall. Aerosol Pb concentrations significantly decreased in 25 years from 74 ± 5 ng/m3 in 1994–1995 to 14 ± 13 ng/m3 measured in Bangkok during Northeast (NE) monsoon winds. Concentrations of all the metals are higher in Chonburi compared to Bangkok in the NE monsoon wind, owing to the addition of local emissions from the megacity over the long-range transported metals before the winds reach the coastal town. The Pb isotope ratios have a wide range (206Pb/207Pb range 1.1343–1.1685 and 208Pb/207Pb range 2.4138–2.4450) but the average ratios are not significantly different in Bangkok and Chonburi for all three seasons. However, present day 206Pb/207Pb ratios are more radiogenic than those measured 25 years ago in Bangkok. The Pb isotopes from both locations in all seasons have considerable overlap with unleaded gasoline and diesel used in Southeast Asia indicating automobile exhaust as an important source. Additionally, the NE monsoon winds are influenced by mixing of crustal dust (Al/Pb ratios correlates well with 206Pb/207Pb, r2 = 0.63) with coal combustion emission (strong inter-correlation of Pb, Zn, As and Cd, r2 from 0.72 to 0.94) from China and Vietnam. Pb isotopes of the Southwest (SW) monsoon winds are also influenced by crustal dust and falls on the mixing line between coal combustion and ore processing emission from India in a Pb triple isotope plot. Chemical composition of aerosols in the inter-monsoon winds are similar to SW monsoon winds. After a quarter-century of leaded gasoline banning in Thailand, the atmospheric Pb sources have changed from less radiogenic leaded gasoline exhaust and Chinese ore processing to more radiogenic unleaded gasoline and diesel exhaust and coal combustion.

Experimental study on effect by cementation on self-sealing capability of bentonite buffer material

In Japanese project for disposal of high-level radioactive waste, the self-sealing capability of bentonite buffer material, which results from the swelling deformation to fill the gaps between waste container and wall of disposal pit, must be retained thousands of years. However, because of the effect of high pressures, occurrence of cementation and property changes of the buffer material are a concern. Few studies had examined cementation effects because of the difficulties for simulating long-term alteration process experimentally. In this paper, swelling properties of consolidated buffer are regarded as similar as those of naturally consolidated bentonite ore. Therefore, three kinds of bentonite ores were used for experiments to elucidate influences of cementation on self-sealing capabilities. Undisturbed and reconstituted specimens were prepared to assess their swelling pressures after filling a preset gap in a swelling pressure apparatus. Results show that for Japanese ores, the swelling pressure of undisturbed specimens is about half that of reconstituted specimens. For American and Chinese ores, the difference of swelling pressure is greater when the preset gap is smaller. Results imply that effects of cementation on self-sealing capability are smaller when swelling deformation is allowed.

Simulating producer responses to selected chinese rare earth policies

This study explores the effects of Chinese rare earth stockpiling, environmental taxation, and improvements in recovery rates on rare earth markets. It uses a Stackelberg model with a leading producer (legal Chinese producers) and two sequential followers (illegal Chinese producers and the Mount Weld mine in Australia), each producing multiple rare earths. The model is parameterized for the production and prices of separated rare earth oxides (REOs) from ore. Counterfactuals involving Chinese policies are compared to the no-policy, business-as-usual (BAU) scenario. The five counterfactuals are: (1) further Chinese State Reserve Bureau (SRB) stockpiling of neodymium, (2) further SRB stockpiling of dysprosium, (3) an environmental tax on the production of legal Chinese rare earths, (4) increased recovery rates of neodymium at legal Chinese operations, and (5) increased recovery rates of dysprosium also at legal Chinese operations. The BAU scenario and five counterfactuals are run with (a) four different levels of reference illegal Chinese production and (b) with and without the Chinese production quota, yielding 48 total outcomes (6×4×2). The first finding is that any SRB stockpile purchase increases the price of the stockpiled REO and increases legal Chinese ore production. However, given co-production, increased ore production involves more production of all REOs, and the prices of non-stockpiled REOs decrease. Thus if the stockpiled REO represents a large (small) portion of illegal Chinese and Mount Weld revenue, then illegal Chinese producers and the Mount Weld mine will increase (decrease) their production. An environmental tax decreases legal Chinese production, increases production by illegal Chinese producers and Mount Weld, and increases prices of all REOs. Increased legal Chinese recovery rates lead to increased legal Chinese production, decreased production by illegal Chinese producers and Mount Weld, and decreased REO prices. Increased levels of reference illegal Chinese production (a) exacerbate the policy-driven production increases or dampen production reductions of illegal producers and (b) conversely, for legal Chinese producers, reduce policy-driven production increases and further increase production reductions.

Experimental Study on Magnetic Roasting of Low Grade Specularite

Along with the continuously rose of the iron ore price and the Chinese iron ore quantity demanded, Iron ore self-sufficient rate has become the bottleneck of Chinese steel industry development. In order to increase Chinese ore self-sufficiency rate, the paper study the xinjiang region low grade specularite. When the crude ore grade is 35%, the mass percent of reducing agent pulverized coal is 12%, roasting temperature is 800°C，roasting time is 50 min, milling fineness is 90% passing 0.074 mm and the magnetic induction is 84kA/m, after a low intensity magnetic separation, the iron concentrate can be got whose yield is 42.83%, grade is 62.04% and recovery is 79.26%.

Research on High-Temperature Properties of Typical Iron Ores Used in China and its Blending Optimization

High-temperature properties of 10 samples of iron ore from Brazil, Australia and China were measured. Several conclusions were made based on these experimental results. Assimilability of Brazilian ore, Australian ore and Chinese ore concentrate were low, high and medium, respectively. Optimal fluidity of liquid phase was observed in 2 types of Brazilian ores (BR-B, BR-C), 1 type of Australian ore (AU-C) and 1 type of Chinese ore (CH-D). For self-strength of the bonding phase, Australian ore presented low levels, while Brazilian and Chinese ore presented high levels. According to the experimental results of high-temperature properties of iron ore, schemes of ore blending optimization were designed and sinter pot test using these blends were performed. The results indicated that ore blends composed of 30~45% Brazilian ores + 25~50% Australian ores + 20~30% Chinese concentrates presented excellent sintering results, considering both the performance of the processing and quality of the sinter. Therefore this experiment has proved that ore blending optimization combining high temperature properties can lead to more efficient sintering mixes.

Biomonitoring of testate amoebae (protozoa) as toxic metals absorbed in aquatic bryophytes from the Hg-Tl mineralized area (China)

Toxic metal pollution in bodies of water is a source of danger to the health of people living in developing countries. The untreated mine wastes located near some Chinese ore mines may cause water pollution, which ultimately results in various diseases. The aim of the present study is to assess the response of testate amoebae communities to pollution by toxic metals in groundwater, stream water, and aquatic bryophytes in Lanmuchang stream located in the Hg-Tl mineralized area in southwestern Guizhou Province, China. Measurements were made of the levels of Hg, As, Cd, Tl, Cu, Zn, and Pb in three mosses: Hyophila propagulifera, Rhynchostegium riparioides, and Hygroamblystegium tenax. Mean moss concentrations of Hg, As, Cu, Pb, and Zn were significantly higher than stream water values and testate amoebae species richness and abundance were significantly lower in the 'polluted' group. We then studied the correlation between toxic metals and testate amoebae. The total species abundance is correlated negatively to Hg and Cu concentrations. Our results indicated that testate amoebae are sensitive to toxic metal pollution and aquatic bryophytes are bioaccumulators of trace metals, and results also showed potential microecosystem health risks.

Sintering Fundamentals of Magnetite Alone and Blended with Hematite and Hematite/Goethite Ores

This work overviews the properties and sintering behaviour of Chinese magnetite concentrates, and interactions between magnetite concentrates and imported hematite, hematite/goethite ores in sintering. Sintering performance of several Chinese ore blends was also presented to provide greater understanding of the behaviour of imported hematite and hematite/goethite ores.Chinese magnetite concentrates are generally more complex in chemistry and mineralogy and less reactive compared to hematite, Marra Mamba and goethite ores. Sinter beds formed from blends containing high level of magnetite concentrate are more deformable, and thus this could reduce their green bed permeability during charging and application of suction. SFCA formation in magnetite sintering occurs primarily in the cooling stage as magnetite oxidation is rather limited prior to the arrival of high temperature zone.Porous hematite and Marra Mamba ores are easy to react and hence assist melt formation. Addition of porous hematite and Marra Mamba ores to magnetite concentrates improves granulation efficiency and sintering performance considerably.

Introduction of Pisolitic Goethite Ore into a Chinese Ore Blend.

Research has been carried out to examine the effects of introducing an Australian goethitic ore (i.e. Yandi ore) into a Chinese sintering ore blend. Bench-scale studies show that Yandi ore is easier to be assimilated than hematite ore, which agrees with that observed in blending with hematite ores. Substitution of Yandi ore for an Australian hematite in the blends does not lead to significant changes in sinter mineralogy. Effects of adding Yandi ore on sintering performance was studied by conducting pot tests under simulated conditions of this Chinese sinter plant. It has been found that when an Australian hematite ore is replaced with Yandi at 10-40 % in blends, at slightly increased mix moisture, productivity maintains or increases slightly, coke rate maintains and sinter strength shows a marginal increase with increasing Yandi ore At Yandi ore levels of 10-40 % the productivity is about 1.47-1.51 t/m 2 h at mix moistures of 7.2-7.3%, ISO tumble index of the sinters is around 69 %, coke rate is about 50 kg/t. The low coke is probably due to the easy-melting property of Yandi ore, possible oxidation of the magnetite concentrates, etc. JIS reducibility of the sinters increases from 60 % to 68% when the goethite ore level varies from 10 % to 40% in the blends. This work evidences that Yandi ore can be used successfully to replace hematite ores in Chinese type blends.

Complex tin-bearing sulphides of the South Chinese ore type

Complex tin-bearing sulphides of the South Chinese ore type