scholarly journals Texture and Geochemistry of Scheelites in the Tongshankou Deposit in Daye, Hubei, China: Implication for REE Substitution Mechanism and Multistage W Mineralization Processes

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 984
Author(s):  
Rui-Zhe Zhao ◽  
Min-Fang Wang ◽  
Huan Li ◽  
Xiao-Yu Shang ◽  
Zaheen Ullah ◽  
...  
Keyword(s):  
Skarn Deposit ◽  
Forming Process ◽  
Multi Stage ◽  
Substitution Mechanism ◽  
Fluid Environment ◽  
Mineralization Processes ◽  
Skarn Deposits ◽  
Granodiorite Porphyry ◽  
Site Vacancy ◽  
Ore District

The Tongshankou skarn deposit in the Edong ore district is a typical metasomatic deposit associated with adjacent granodiorite porphyry and carbonate rocks. Using comprehensive microscopic observations, mineralogical and geochemical analysis, scheelite grains in the skarns can be classified into three major types, showing multi-stage mineralization characteristics. In the redox fluid environment, scheelites that occur with garnets usually have affinity to garnets, while in later skarn phases others exist with oxides and sulfides. They can be subdivided by trace elements, such as Nb and Eu, to discuss the detailed ore-forming process. Scheelites have three typical substitution mechanisms including: 2Ca2 + ⇌ REE3 + +Na+ (1); Ca2 + + W6 + ⇌ REE3 + +Nb5+(2); and 3Ca2 + ⇌ 2REE3++ □Ca (□Ca = Ca site vacancy) (3). Plagioclase or various hydrothermal stages can cause Eu anomalies to fluctuate from positive to negative, and these processes can cause particular zonation in W and Mo contents in scheelites. This study highlights the use of texture and geochemistry of scheelites in skarn deposits, depicting the W mineralization processes.

scholarly journals Constraints from Pyrite Micro-Structures on Gold Mineralization Processes of Multi-Stage Fluid Episodes

2020 ◽  
Author(s):  
Wei Tan ◽  
Steven M. Reddy ◽  
Denis Fougerouse ◽  
Christina Yan Wang ◽  
Hongping He
Keyword(s):  
Gold Mineralization ◽  
Multi Stage ◽  
Mineralization Processes ◽  
Micro Structures

scholarly journals Iron Isotopes Constrain the Metal Sources of Skarn Deposits: A Case Study from the Han-Xing Fe Deposit, China

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 951
Author(s):  
Bin Zhu ◽  
Hongfu Zhang ◽  
M. Santosh ◽  
Benxun Su ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
Major Elements ◽  
Ore Deposits ◽  
Magmatic Fluid ◽  
Skarn Deposit ◽  
Mass Balance Calculation ◽  
Positive Correlation ◽  
Fe Isotopes ◽  
Magmatic Fluids ◽  
Skarn Deposits

Magmatic fluids and leaching of rocks are regarded as the two sources of magmatic hydrothermal deposits, but their relative contributions to the metals in the deposits are still unclear. In this study, we combine major elements and Fe isotopes in two sets of rocks from the Han-Xing iron skarn deposit in China to constrain the iron sources. The positive correlation between the δ56Fe and ∑Fe2O3/TiO2 of altered diorites (∑Fe2O3 refers to the total iron) demonstrates that heavy Fe isotopes are preferentially leached from diorites during hydrothermal alteration. However, except for the pyrite, all the rocks and minerals formed in the skarn deposit are enriched in the light Fe isotope relative to the fresh/less altered diorites. Therefore, besides the leaching of rocks, the Fe isotopically light magmatic fluid also provides a large quantity of iron for this deposit. Based on the mass balance calculation, we conclude that iron from magmatic fluid is almost 2.6 times as large as that from the leaching of rocks. This is the first study to estimate the relative proportions of iron sources for Fe deposits by using Fe isotopes. Here, we propose that the high δ56Fe of magmatic intrusions combining the positive correlation between their ∑Fe2O3/TiO2 and δ56Fe could be taken as a fingerprint of exsolution or interaction with magmatic fluids, which contributes to the exploration of magmatic hydrothermal ore deposits.

scholarly journals Fastener products lightweight design and forming process simulation

2018 ◽  
Vol 185 ◽  
pp. 00030
Author(s):  
Jinn-Jong Sheu ◽  
Chien-Jen Ho ◽  
Cheng-Hsien Yu ◽  
Kuo-Ting Wu
Keyword(s):  
Topology Optimization ◽  
Lightweight Design ◽  
Integrated Design ◽  
Optimization Method ◽  
Design System ◽  
Forming Process ◽  
Multi Stage ◽  
Die Stress ◽  
Final Design ◽  
Evaluation Stage

In this research, an integrated design system was established to design the product of nuts with flange and generate the lightweight geometry of product. The multi-stage forming process was evaluated using the CAE simulations. The topology optimization method was used to achieve the lightweight design, that included keeping necessary geometrical features and remove the excess volumes. The topological discrete model had been remodelled into a meaningful geometry which is able to satisfy the requirement of proof load of fastener specification. The final design of the lightweight geometry was adopted to test the capability of carrying proof load required using CAE simulations with the boundary conditions of the related ASTM standard. In the evaluation stage, the finite element method was used to do the topology optimization, the proof load evaluation, the forging process and the die stress analysis. The simulation results showed the lightweight design was able to reduce the weight of product and maintain enough mechanical strength. The proposed process and die designs were able to obtain the lightweight product without defects.

Finite-Element Modeling of Thermal Forming of Ti-TWBs with Experimental Verification

2014 ◽  
Vol 626 ◽  
pp. 518-523
Author(s):  
C.P. Lai ◽  
Luen Chow Chan
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Experimental Verification ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Production Test ◽  
Forming Process ◽  
Tailor Welded Blanks ◽  
Multi Stage ◽  
Strain Paths

The titanium tailor-welded blanks (Ti-TWBs) are being developed in different industries such as automobile and aerospace, combining the advantages of both tailor-welded blanks technology and titanium alloys. In recent decades, computer simulation of sheet metal forming processes has been employed increasingly over conventional production test and adjustment methodology to achieve the optimum and cost-effective operation procedures. Recently, certain amounts of theoretical analysis for the sheet metal forming process have been developed. However, these analyses could not be applied directly to the material under multi-stage forming process. Thus, some researchers have developed a damage-based model to predict the instability and failure of sheet metals, particularly for the above Ti-TWBs, with consideration of material damage under discontinuous or proportional loading strain paths. So far this model has been used and proved to be successful to predict formability of selected sheets of steel and aluminium alloy. However, the application of the damage-coupled model has yet to be extended to the Ti-TWBs under thermal multi-stage forming operation.The main objective of this paper is to investigate numerically the formability of Ti-TWBs under multi-stage forming process with experimental verification. Titanium alloy sheets (Ti-6Al-4V) in thickness of 0.7mm and 1.0mm were selected and laser-welded the specimen of Ti-TWBs. The model based on the damage mechanics is introduced to predict the thermal formability of Ti-TWBs with change of strain paths. In this study, the anisotropic damage model incorporate with the finite element codes and user-define material subroutine were developed to predict the formability of Ti-TWBs with change of strain paths. The mechanical properties and damage parameters of Ti-TWBs for the simulation were measured experimentally. The simulation of Ti-TWB under multi-stage forming process were then conducted and validated experimentally at similar forming conditions. The predicted results have been found to agree well with those obtained from the experiments. This analysis can be applied readily to design and manufacture TWB components or structures so as to satisfy the need of such market demands.

Finite Element Simulations Of Multi Stage Incremental Forming Process

2018 ◽  
Vol 5 (2) ◽  
pp. 3802-3810 ◽  
Author(s):  
Kurra Suresh ◽  
Srinivasa Prakash Regalla ◽  
Nitin Kotkundae
Keyword(s):  
Finite Element ◽  
Incremental Forming ◽  
Finite Element Simulations ◽  
Forming Process ◽  
Multi Stage

Optimum Design of Forming Sequence of One-Piece Automobile Steel Wheels without Welding Using Finite Element Simulation

2007 ◽  
Vol 340-341 ◽  
pp. 773-778
Author(s):  
Y. Abe ◽  
J. Watanabe ◽  
Kenichiro Mori
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Optimum Design ◽  
Deep Drawing ◽  
Outer Side ◽  
Forming Process ◽  
Multi Stage ◽  
Element Simulation ◽  
Automobile Steel ◽  
The One

A forming sequence of one-piece automobile steel wheels without welding was designed. In this forming process, the one-piece wheel was formed from a circular blank only by multi-stage stamping operations, and a deeply drawn cup was formed into the wheel. Two humps of the rim flange for fixing the tire were formed in the flaring and flanging stages. The humps of the rim in the opening and outer side were formed by buckling the inner flange of the rim, and by swelling the outer flange with an upper die having a short land, respectively. In addition, the number of stages was considerably reduced from 16 stages to only 9 stages by combining the deep drawing and ironing stages and by adding a holding die in the flaring stages. The forming sequence of the one-piece wheels was evaluated by both finite element simulation and miniature experiment.

Investigation into Influence of Pre-Forming Depth on Multi-Stage Hydrodynamic Deep Drawing of Thin-Wall Cups with Stepped Geometries

2012 ◽  
Vol 457-458 ◽  
pp. 1219-1222 ◽  
Author(s):  
Yu Zhu ◽  
Min Wan ◽  
Ying Ke Zhou ◽  
Qing Hai Liu ◽  
Nan Song Zheng ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Failure Modes ◽  
Thickness Distribution ◽  
Steel Part ◽  
Drawing Ratio ◽  
Thin Wall ◽  
Forming Process ◽  
Hydrodynamic Deep Drawing ◽  
Multi Stage ◽  
Thin Walled

Hydrodynamic deep drawing (HDD) is an effective method for manufacturing complicated and thin-walled parts. Aiming at the forming process of the stainless steel part with 0.4 mm thick and complex stepped geometries, the technology scheme of multi-stage HDD assisted by conventional deep drawing (CDD) is proposed in consideration of wrinkling and destabilization in the unsupported region of the conical wall, and finite element models are built. As a key process parameter, pre-forming depth on the quality of the parts is explored with assistance of numerical simulations and verification experiments. Furthermore, the failure modes, including wrinkling and fracture during forming process are discussed; meanwhile, the optimum pre-forming depth is realized. The results indicate that the technological method is proven to be feasible for integral forming of thin-walled parts with a large drawing ratio and stepped geometries; moreover, the parts with uniform thickness distribution and high quality are successfully formed by adopting optimum pre-forming depth.

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