scholarly journals Two-stage SART process: A feasible alternative for gold cyanidation plants with high zinc and copper contents

2018 ◽  
Author(s):  
Humberto Estay ◽  
Minghai Gim-Krumm ◽  
Michelle Quilaqueo
Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 392 ◽  
Author(s):  
Humberto Estay ◽  
Minghai Gim-Krumm ◽  
Michelle Quilaqueo

The SART (sulfidization, acidification, recycling, and thickening) process (SP) has been successfully implemented in gold cyanidation plants to address issues associated with high cyanide-soluble copper content ores. However, this process could produce a relatively low grade precipitate, decreasing the sale price when gold plants have high zinc and copper content in their solutions. A potential option in this case would be the use of a two-stage SART process (TSSP) to produce separate zinc and copper precipitates. The additional equipment involved with this process would increase the capital cost, thereby generating concerns about the optimal range of metal contents that could justify this option. This study presents a methodology to quantify the feasible range of Cu/Zn concentrations that would justify a two-stage SART process. The study is based on a thermodynamic model and a simple economic evaluation. Results show the TSSP is preferred when the Cu/Zn ratio ranges between 0.2 and 1.5 with copper concentration higher than 500 mg/L. The TSSP appears to be a viable option to consider for gold plants having concentrations of copper and zinc higher than 200 mg/L for both metals.


2018 ◽  
Vol 35 (4) ◽  
pp. 323-332 ◽  
Author(s):  
Guido Torzilli ◽  
Luca Viganò ◽  
Matteo Cimino ◽  
Katsunori Imai ◽  
Eric Vibert ◽  
...  

Background: Two-stage hepatectomy (TSH) is the present standard for multiple bilobar colorectal metastases (CLM). As alternative, ultrasound-guided one-stage hepatectomy (E-OSH) has been proposed even for deep-located nodules to compare TSH and E-OSH. Methods: All consecutive TSH at the Paul Brousse Hospital and E-OSH at the Humanitas Research Hospital were considered. The inclusion criteria were ≥6 CLM, ≥3 CLM in the left liver, and ≥1 lesion with vascular contact. A total of 74 TSH and 35 E-OSH were compared. Results: The 2 groups had similar characteristics. Drop-out rate of TSH was 40.5%. In comparison with the cumulated hepatectomies of TSH, E-OSH had lower blood loss (500 vs. 1,100 mL, p = 0.009), overall morbidity (37.1 vs. 70.5%, p = 0.003), severe morbidity (14.3 vs. 36.4%, p = 0.04), and liver-specific morbidity (22.9 vs. 40.9%, p = 0.02). R0 resection rate was similar between groups. E-OSH and completed TSH had similar overall survival (5-year 38.2 vs. 31.8%), recurrence-free survival (3-year 17.6 vs. 17.7%), and recurrence sites. Conclusions: E-OSH is a safe alternative to TSH for multiple bilobar deep-located CLM. Whenever feasible, E-OSH should even be considered the preferred option because it has excellent safety and oncological outcomes equivalent to completed TSH, without the drop-out risk.


Author(s):  
Sengshiu Chung ◽  
Peggy Cebe

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.


2007 ◽  
Vol 177 (4S) ◽  
pp. 121-121
Author(s):  
Antonio Dessanti ◽  
Diego Falchetti ◽  
Marco Iannuccelli ◽  
Susanna Milianti ◽  
Gian P. Strusi ◽  
...  
Keyword(s):  

2007 ◽  
Vol 177 (4S) ◽  
pp. 120-120
Author(s):  
Pamela I. Ellsworth ◽  
Anthony Caldamone
Keyword(s):  

2005 ◽  
Vol 38 (18) ◽  
pp. 68
Author(s):  
SHARON WORCESTER
Keyword(s):  

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