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By M. Sanchez

In the last decades, the Chilean copper mining and metallurgical industry have had to modify their technological processes to meet the environmental regulations implemented by the Chilean government, and also to support the pressure of the public opinion. Thus, air quality standards for sulfur dioxide and particulate matter (primary and secondary), plans for reducing emission of arsenic by the Chilean copper smelters, effluents discharge limits, among others regulations were applied by the environmental agency. Additionally, agreements on cleaner production were carried out by mining sector and government. Now, a draft law on mine closure, and another on environmental mining wastes (abandoned mines) are being discussed by the authorities and the mining sector. In the context, production and environmental impacts in different ways to produce copper in the Chilean mining industry are reviewed and regulatory tendencies as well as abatement technologies today used are exposed and discussed in this presentation. Pyro, hydro and electrometallurgical processes employed and their current effluent and contaminants are presented showing various alternatives of treatment in the copper industry. An update of regulations established in Chile vis a vis copper production, with an especial attention to mine closure are also presented.

Jan 1, 2007

By George Meadows

Consultation and Accommodation Introductions Consultation -Best Practices The Role of Negotiations The HVC Experience Summary / Conclusions The Challenge Meeting legal and policy obligations to consult while adhering to project priorities, timelines and budgets Defining who needs to be consulted, by whom, and ?how much?? Accommodation ?who is responsible and what is the appropriate scope? Social License -establishing positive working relationships with First Nations involved in project review / approvals / implementation in a manner that advances the interests of all parties

May 1, 2010

By T. Krumins, L. Zunti, R. Frischmuth

Mercury is known to occur in sulphide-bearing refractory gold deposits in the form of sulphide minerals or elemental inclusions. These deposits typically require an oxidative pre-treatment process, such as pressure oxidation or roasting, to achieve economic gold recovery. However, these processes also have the potential to liberate mercury, a portion of which may then be released to the environment through gaseous emissions. Mercury emissions from mine processing operations have been of particular interest in recent years, as governments impose lower emission targets and organizations adopt better industry practices to reduce the environmental and health aspects of releasing mercury into the environment. This paper describes various mercury removal technologies with respect to pressure oxidation gas handling circuits, with a focus on key design variables and technology selection criteria.

Jan 1, 2014

By M. Uszko

The climatic area in which Poland is located requires heating the ventilation air at intake shafts during the winter season. Air heating of the intake shaft should ensure safe operation of hoisting devices; while at the same time it also affects the conditions of the mine environment. The paper presents the issues of shaft heating in coal mines in terms of the mining law, the effect on the conditions of the mine environment and heating technology solutions used in the mines of Kompania Weglowa S.A. (KWSA).

Aug 1, 2013

By K. Esmaieli

The Synthetic Rock Mass (SRM) approach has the potential to capture the mechanical behavior of large rock samples. In order for the method to be used with confidence it is necessary to gain a good understanding of the factors that influences its analysis. This paper reports on a series of numerical experiments, based on field data from a large underground mine, to investigate the influence of intact rock mass strength of a constructed (SRM). A jointed rock mass defined by three fracture sets was simulated by a Discrete Fracture Network (DFN) model. The generated fracture network was subsequently embedded into six different intact rock samples, simulated by a bonded particle model in PFC3D, generating six SRM samples. Each intact rock sample was 7 m × 7 m × 14 m and assigned different mechanical properties. The first intact rock sample was assigned a uniaxial compressive strength of 205 MPa and an elastic modulus of 104 GPa with the UCS and elastic modulus values of the other samples downgraded by 10% until the weakest sample had a UCS value of 121 MPa and an elastic modulus value of 61 GPa. All SRM samples were loaded under uniaxial compression to obtain the complete stress strain curve. It was observed that the compressive strength of the rock mass samples decreased by 10% following the same trend as the rock material strength. However, the elastic modulus of the rock mass samples decreased non-linearly with reduction of the elastic modulus of the rock material. The Poisson's ratio of rock mass samples does not change with decrease of rock material properties. For the post-peak behaviour the results show that both the brittleness index and the residual strength of rock mass samples decreased as the rock material properties degrades.

Aug 1, 2013

By C. O. Aksoy, H. Kose, K. Ozfirat, T. Malli, A. Gonen, S. Gurgen

In selecting mobile mining equipment, factors including availability, useful economic life, maintenance and operating costs, and spare parts availability are considered. Given these factors, trucks and shovels with different capacities are selected. Optimizing equipment for pit and hillside quarry cases, where 8% and 10% ramps are commonly in use, were examined; the effect of other mining activities such as drilling and blasting on unit cost were considered. In principle, 20 m to 25 m high benches should be economical for downhill haulage, and 7 m to 10 m low benches economical for uphill haulage. However, practice of both mining styles favours 10 m to 15 m bench heights. Hence, the analysis here was carried out with the field experience bench height range. In the study, a truck-shovel optimization was based on the movement of 5 to 20 million cubic metres (in 2.5 million cubic metre increments) of overburden stripping at the Eynez open pit mine in the Soma region of Turkey. The outcome showed that low-capacity shovels were unfavourable due to high production expectations. High-capacity shovels were also unfavourable due to health and safety issues causing high instances of impact vibration on trucks during the loading cycle and a decrease in foreseeable unit lifetimes. The number of shovel passes required to load a truck ranged from three to six. Trucks with high-capacity bodies were deemed uneconomical due to high investment and operating costs.

Jan 1, 2005

By A. S. Nortjé

At South Deep Gold Mine longhole stopes are backfilled using a cemented Cyclone Classified Tailings in its hydraulic state. The need to contain the hydraulic fill until cured requires a barricade. Due to the massive size of the stopes, the tailings can exert enormous forces on any such barricade. Barricades have long been in use, but recent failures in Australia and the large rate of filling required at South Deep solicited a robust design. A robust design must examine all foreseeable failures and the barricade must be able to resist all expected and, within limits, unexpected loads. The design should also be simple to construct and cost effective, limiting the impact of construction errors and unnecessary delays to production.

May 1, 2007

"Ground control research in underground coal mines has been ongoing for over 50 years. One of the most problematic issues in underground coal mines is roof failures associated with weak shale. This paper will present a historical narrative on the research the National Institute for Occupational Safety and Health has conducted in relation to rock mechanics and shale. This paper begins by first discussing how shale is classified in relation to coal mining. Characterizing and planning for weak roof sequences is an important step in developing an engineering solution to prevent roof failures. Next, the failure mechanics associated with the weak characteristics of shale will be discussed. Understanding these failure mechanics also aids in applying the correct engineering solutions. The various solutions that have been implemented in the underground coal mining industry to control the different modes of failure will be summarized. Finally, a discussion on current and future research relating to rock mechanics and shale is presented. The overall goal of the paper is to share the collective ground control experience of controlling roof structures dominated by shale rock in underground coal mining.INTRODUCTIONThe National Institute for Occupational Safety and Health’s (NIOSH) Office of Mine Safety and Health Research (OMSHR), formerly the United States Bureau of Mines, has been conducting research on ground control safety for over 50 years. The overall objective of the research is to reduce underground mining injuries and fatalities by characterizing roof conditions, improving roof support performance and application, and optimizing pillar design and mine layout. Underground mining has one of the highest fatal injury rates of any industry in the United States—more than five times the national average compared to other industries (CDC, 2012). Roof fall injuries can be severe, resulting in lacerations, bone fractures, amputations, and death. Non-injury roof falls can also be problematic, resulting in lost production, delays, blockage of primary escape routes, disruption to ventilation, and hazardous rehabilitation conditions.Coal mining is increasingly subject to more adverse geological conditions. Weak roof can be found in all coal mining regions in the United States, but there are a few geographically isolated areas with higher roof fall rates contributed to by particularly poor roof conditions, as represented in Figure 1. This figure shows that when non-injury roof fall rates are normalized to production, the Illinois Basin and Central/Northern Appalachia regions have the highest rates. These isolated regions have inherently weak roof even before mining has occurred, and this roof is easily damaged during the mining process. The weak roof in these regions consists primarily of shale. Shale can be troublesome in underground coal mining because it can appear massive but easily splits along bedding planes and is often moisture-sensitive."

Jan 1, 2015

By Roger Lafrance

"This paper discusses various aspects affected by the use of large-diameter boreholes in underground mines. Topics covered consist of noxious fumes, vibrations, post-blast effects, various types of explosives, the cordine system in production blasts, the slider primer system and wall-control methods. In general, the paper is an overview of this important fact of underground mining.IntroductionWith economical factors leading the way, many reasons motivated drilling equipment companies to develop equipment that can drill holes up to eight inches in diameter and even larger for underground applications. One of these other reasons is the fact that many orebodies were considered marginal, given the high costs of conventional mining methods utilizing small diameter boreholes. With these criteria in mind, accelerated programs were put in motion to develop equipment that would reduce both-development and production costs in underground mines. Change s in any basic program often affect other areas down the line. This is particularly true with the ad vent of large-diameter boreholes underground.C-I-L Inc. is certainly no stranger to this phenomena. Whether production headings increase in size and tonnage or whether production increases due to lower costs, one fact remains unchanged and that is the fact that all development and production holes are loaded and blasted whether they be of small or large diameter. Due to this fact, C-I-L Inc., as a leading explosives manufacturer, initiated a program to examine blasting methods in use in surface work with the intent of revising these method s for underground applications. Research facilities were also oriented toward developing appropriate products. This was a task that was accepted with anticipation, with the result that many new blasting systems and methods were brought forward, thanks to the collective efforts of both the consumers and manufacturers."

Jan 1, 1984

By T. Patching

"Introduction The occurrence of coal was first reported in the Drumheller area in 1793 but it was not until 1912 that production of coal was recorded. In that year 13,000 tonnes were mined in the Drumheller area. Three years later the Drumheller mines ranked next in the Province to those in the Crowsnest and Lethbridge districts, with an output of 225,000 tonnes. By 1917 production had increased to 600,000 tonnes, moving Drumheller to second place in output in the province, second only to the Crowsnest district. It held this rank until 1960. Production, almost all from underground mining, rose to over a million tonnes a year by 1920 and remained between one and two million tonnes per year until 1954. Competition from newly discovered oil and natural gas, beginning around 1950 caused a steady loss of domestic coal markets, especially from underground mines. By 1960 Drumheller's production had fallen below a half a million tonnes per year and the field ranked third in output in the province, being surpassed by new stripping operations in the Castor field. By 1965 only a couple of producing mines remained in the Drumheller valley, and output was only about a quarter of a million tonnes per year(1). Throughout the life of the field production was seasonal, depending mainly on the domestic heating market. In 1979 the last mine ceased production. For the last several years of its operation it had remained open in the summers to provide tours for visitors(2). The Drumheller mining operations were located along or near the Red Deer River valley which is 300 to 400 feet deep, and extended from a few miles above the city of Drumheller to East Coulee, about 13 miles down the river in a south-easterly direction. Intervening mining communities existed for some years at Wayne and Rosedale. During the peak years of production some 2000 to 2500 miners and their families lived in these communities and the surrounding areas."

Jan 1, 1985

By H. Sano

Most of the dust generated from the copper smelting process in Chile has been stored after the stabilization by hydrometallurgical process because it contains high concentrations of arsenic. However, in recent years, the dust generation has increased because of degrading the quality of concentrate. In addition, the environmental regulations become stricter. On the other hand, valuable metals such as copper and zinc are contained in the dust at high concentrations and it is desirable to recover them. In this study, the effect of dust recirculation to the smelting process was examined in order not only to decrease the amount of dust but also to recover copper. Dust generation and the distribution of arsenic, lead, zinc etc. among the matte, slag and gas phases were evaluated as a function of the amount of recirculated dust, partial pressure of oxygen and temperature. It was found that the direct dust return to the smelting process was quite effective for the recovery of copper and the reduction of dust generation, but the acceptable dust amount was limited by the produced matte quality.

Jan 1, 2007

By W. D. Madeley

Synthetic minerals were made from pure starting materials and galena samples were doped with the title metals. Microscopic, microprobe and X-ray examination confirmed that the dopeants were in solid solution. Paired flotations in a Hallimond-tube apparatus were performed to determine relative flotation response using Aerofloat 238 promoter. Results of these tests show that silver-doped galena floats more readily than pure galena and that galena doped with bismuth floats less readily than pure mineral to a 95% confidence level. Galena doped with both silver and antimony as AgSbS2 shows no detectable effect. Antimony-doped galena followed the expected trend, but not to 95% confidence. The results are consistent with the theory that flotation by thiol-type anionic collectors is enhanced by p-type semiconduction.

Jan 1, 1978

By D. Kong, A. Klyashtorin, L. McGilp, I. Wilson

This work reports on applying iron oxide coated sands media in an experimental permeable reactive barrier to remove uranium species from uranium containing water. A field experiment was conducted at the legacy Gunnar uranium mine & mill site that was abandoned in the 1960s with limited to no decommissioning. The flooded Gunnar mine pit presently contains about 3.2 million m3 of water contaminated by dissolved U (1.2 mg/l), Ra-226 (0.4 Bq/l), and minor concentrations of other contaminants (As, Se, etc.). The water is seeping over the pit rim into Lake Athabasca posing environmental and health concerns. Iron oxide coated sands can be used to immobilize uranium species through an adsorption process. Methods for preparation of hydrous ferric oxide sorbents and their supported forms onto silica sands are described. Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (pXRD) were used to characterize the physical-chemical properties of the sorbent. The monolayer uranium uptake capacity (Qm) was estimated through the Langmuir adsorption isotherm. Adsorption kinetic experiments were performed in a lab environment before moving to a field trial. Based on these lab results and the input on field-scale appropriate geometries, a pilot permeable reactive barrier was fabricated and a field test conducted near the Gunnar pit in June 2019. This pilot test provided technical data and information needed for designing a full-scale permeable barrier based on the iron oxide coated sands, which may be applied for in-situ water treatment at Gunnar and other legacy uranium sites.

Jan 1, 2020

By Rod Maclean, George Stewart

"This paper covers the planning, development, and mining of an underground pillar complex using a bulk mining method. To achieve the long-term goal of continually improving our operating processes, all cut-and-fill and undercut-and-fill workplaces at Thompson Mine have been evaluated for their conversion potential to the bulk method referred to as VerticalBlock Mining (V.B.M.).Since December 1979, conversion has occurred to the extent where 80% of the ore hoisted is mined using Vertical Block Mining (V.B.M.).Productivity and profitability have been substantially improved by converting to this bulk method, especially in pillar areas.IntroductionThompson Mine is a 6000 ton per day underground nickel mine located 3 miles outside the City of Thompson, 400 air miles north of Winnipeg . The mine has two shafts, T-l and T-3 (Fig. 1). The T-l shaft is 4427 feet deep with the deepest mining taking place on 4000 level. The T-3 shaft, which is the area of this presentation, extends to a depth of 2607 ft with the deepest operating level at 2400 ft. The two shafts, some 10 000 ft apart, are connected underground on numerous levels. The ore mined at T-3 is trammed on 2400 level to the T-I main ore pass and hoisted through the T-l shaft. Eight hundred and fifty thousand cubic feet of fresh air per minute ventilates the mine.The 1400 level 310 pillar complex is located in the T-3 mine area. There are six rib pillars, two crown pillars and one main pillar (boundary pillar between cut-and-fill stopes) within the complex (Fig. 2). The majority of the ore in this area has been mined using mechanized cut-and-fill techniques .Undercut-and-fill mining was the method originally planned to recover these pillars. It is slow, labour-intensive, and requires extensive use of timber during the mining cycle. The extraction drifts in the area are heavily timbered due to their proximity to the ore and the age of the facilities. Increasing drift maintenance costs and the successful mining of two main pillars with V.8.M. techniques provided the stimulus to review the mining plans for this area."

Jan 1, 1988

By Hrayr Agnerian

The fair market value of an exploration property is determined by its potential to host a mineral deposit. This potential is gauged by the results of previous exploration, exploration stage, meaningful past expenditures and remaining targets that are not yet tested. Values of exploration properties can be viewed as distinct points in a three-dimensional space defined by orthogonal axes, namely: Exploration Stage (x-axis); Cumulative Expenditures (y-axis); and Property Value (z-axis). In general, these values are estimated by applying activity factors on previous exploration expenditures, e.g. an activity factor of 100% for an active property with good potential and a factor of 50% for an active property but past expenditures have not upgraded the property. At certain periods, a market factor may also be applied to reflect the activity of mineral property acquisitions. For properties that do not exhibit any exploration potential, only nominal values are applied.

Jan 1, 1996

By G. A. Gillett, C. F. Bonney

"The Davy McKee combined mixer-settler (CMS), is a liquid-liquid contactor, which has been commercially applied to the recovery of uranium from dilute sulphuric acid-bearing leach liquors. CMS differs from most other solvent extraction systems in that the mixing and separation of the phases is carried out in the same vessel.IntroductionTypical solvent extraction plants for the recovery of uranium operate at organic to aqueous feed flow ratios of 1 : 2 to 1 : 30. Because it is beneficial to mix the organic and aqueous phases at an organic/aqueous (O / A) ratio of between I : 2 and 2 : I there is incompatibility between the over-all and operating O /A ratios.Conventional mixer-settler designs require an external recycle of the minority flow which results in the possibility of over-mixing, increased settling requirements and entrainment losses. Other workers have approached this problem in terms o f enhanced sett ling and this has been partly successful.Davy McKee's approach involved a radical rethink of the principles of liquid-liquid contact and separation.Description of CMSThe CMS has the important advance that the required mixing O/A ratio can be achieved without external recycle and is not affected by the O /A ratio of the feeds. Three zones co-exist within the CMS unit-a central mixing zone and upper and lower separation zones. A pump impeller on a draught tube is installed within the mixing zone and baffles are installed above and below the mixing zone. Conventional mixer- settlers have several undesirable features which ca n largely be eliminated using the CMS system:"

Jan 1, 1983

By Y. W. Pan, Y. R. Liu

The disturbed natural rock mass tends to equilibrium state accompanying with non-equilibrium evolution process which has significant influence on the long-term stability of engineering structure. The deformation development in the non-equilibrium evolution is determined by two intrinsic processes, trend to equilibrium and damage development, which can be illustrated by evolution of excavated tunnel. Thus the creep and damage must be taken into account in study of non-equilibrium evolution process. Within Rice’s irreversible thermodynamics with internal state variable (ISV), the conjugate force function which equals to zero is a convex surface which divide the stress space into two parts, called equilibrium and nonequilibrium stress space respectively. The concept of effective stress of non-equilibrium has been proposed, in which the stress difference (d - d ) are the effective driving forces of non-equilibrium evolution process with hardening and damage effective. The formulations of inelastic strain rate and energy dissipation rate have been recast in the form of effective stresses. The inelastic complementary energy (ICE) is proposed to measure intensity of non-equilibrium evolution of material system. The specific equations of conjugated forces and kinetic equations of internal state variables are presented. The ICE and rate of energy dissipation are all calculated to be used to evaluate long-term stability of geo-engineering. The results show that rate of energy dissipation may be more convenience and flexible than ICE for internal state variable constitutive equation of rock mass.

Jan 1, 2015

By Thomas G. Madgwick

Introduction Development of oil and gas is still centred in the Province of Alberta, much as it was when C. C. Ross read a paper on this subject three years ago at the Annual General Meeting in Montreal; but so far as gas is concerned, its early production in Saskatchewan seems now assured. The three years that have elapsed since Mr. Ross' paper have witnessed a growth in the world's production of oil that has created a potential supply out of all proportion to the demand for petroleum products, and one that has resisted the most energetic efforts of the industry entirely to control. The natural result has been very much to retard the active prospecting of new structures in the Prairie Provinces with any immediate view to oil production, although the same factor has not hindered the search for gas to the same extent. One consequence has been to divert the attention of organized oil operators from wildcat drilling to more detailed geological investigation than had hitherto been customary, sometimes accompanied by test drilling with a view to the elucidation of geological structure rather than to the immediate development of production which at the present is not needed. Nevertheless, in spite of the growth of this phase of oil prospecting - which the writer would be the last not to welcome as a very real blessing and of far greater value than indiscriminate wildcat drilling in either the complex structures of the foothills or the simpler but largely concealed formations of the plains- it is most satisfactory to have to record that in these three years the growth of production both of naphtha and the heavier crude-oil has kept pace with the by no means inconsiderable growth in the production and utilization of natural gas.

Jan 1, 1929

By K. C. Sole, G. Robinson, M. S. Moats, W. G. Davenport, S. Sandoval

Global practice in hydrometallurgical production of copper cathode by electrowinning is reviewed, based on individual plant operating data for 2018. Data from 29 plants were collected, representing 38% of world cathode copper production. Similar surveys were carried out in 1997, 1999, 2003, 2007, and 2013. This survey includes analysis of historical and current data. Evolving trends in operating conditions and performance, as well as equipment design and process technology choices, are analysed and differences in operating practices with location are assessed. Examples of recent technology and operational choices to increase productivity, improve copper quality, and decrease electrical energy consumption are discussed. Significant project expansions, particularly in Africa, and the consolidation of numerous small Chinese operations are also presented. INTRODUCTION Global trends and operating practices in copper electrowinning (EW) in 2018 are reviewed and evaluated. Similar world and African surveys were carried out in 1997, 1999, 2001, 2002, 2003, 2007, and 2013 (Robinson, Davenport, & Jenkins, 1997; Jenkins, Davenport, Kennedy, & Robinson, 1999; Davenport, Jenkins, Robinson, & Karcas, 2001; Robinson, Garbutt, & Davenport, 2002; Robinson, Davenport, Jenkins, King, & Rasmussen, 2003; Robinson, Davenport, Moats, Karcas, & Demetrio, 2007; Robinson, Sole, Sandoval, Moats, Siegmund, & Davenport, 2013). Contributing operations included sites from the USA and Mexico (9), Chile and Peru (6), Laos (1), Kazakhstan (1), and Africa (9). Despite fewer contributions compared with past experience, this survey nevertheless represents 2018 copper EW cathode production of 1.76 Mt, or about 38% of world production of 4.64 Mt (International Copper Study Group, 2017). This drop in permission to contribute is attributed to the more competitive nature of the industry and unprecedented production pressures; furthermore, several operations in Australia have shut down, while large operations that are currently commissioning or ramping up to full production in Africa and Asia declined to participate. Of the Chinese operations, which represent an increasingly important proportion of global electrowon cathode copper, particularly in Africa, only Tenke Fungurume (Democratic Republic of Congo; DRC) participated in this survey.

Jan 1, 2019

By E. Heikkinen, J. Suikkanen, T. Siren, J. Valli, M. Hakala

Diametrically faced borehole breakout observations are a fairly good indication of magnitude of the secondary stresses acting perpendicular to the borehole. In cases of low in situ stresses, where borehole breakouts are not observed naturally, it is possible to increase the prevailing stress state around the borehole by increasing the rock temperature. When the temperature is increased sufficiently, thermally induced borehole breakouts will occur. By implementing the temperature increase in boreholes located at excavated tunnels, it is also possible to study the effect of the near-field stresses caused by the excavation. The near-field stress state changes as a function of borehole depth, thus increasing the information available from experiment. To study the feasibility of this proposed low cost method, a Borehole Thermal Spalling (BTS) experiment was executed in ONKALO Underground Rock Characterization Facility, in Western Finland in 2014. The first borehole pilot test with the method was conducted in ONKALO at the POSE niche in already at May 2010, with the second pilot test following in August 2010 at Äspö HRL. The major objective of the experiments was to define the trend of the maximum in situ stress component, while also providing knowledge of the in situ spalling strength of the ONKALO rock mass. The stress state in ONKALO is nearly isotropic in horizontal layer, causing problems for the use of more traditional stress measurement methods. With boreholes heated over long interval, the weakest rock parts are observed to fail, thus providing statistical confidence. For these reasons, continuous test sections have an advantage in ONKALO, compared to spatially limited stress measurement methods such as overcoring and hydraulic fracturing. The BTS experiment is conducted in 9 meter deep vertical boreholes located at the POSE niche, situated -345 m depth below the ground surface. The boreholes used within the BTS experiment are located in migmatitic granite, in an experiment area where the surrounding stress state and the rock strength are fairly well known. The prior knowledge of the stresses is favourable for the experiment, as it requires careful planning and iterations to determine the appropriate heating power domain. Too low heating power will not be sufficient to cause borehole breakout, while too high heating power causes breakout in all directions thus making determination of stress direction hard or impossible. The initial state of the borehole and induced borehole breakouts will be monitored using acoustic televiewer logging (ABI) and optical borehole logging (OBI) imaging techniques. Fracture mechanics modelling is used in planning of the experiment, also in back-analysis to link the observed breakout angle to stress state. Both the pilot test in 2010 and BTS test in 2014 resulted in similar borehole breakout direction. The results are in line with so called EDZ & VT1 stress interpretation, revealed the maximum horizontal component bearing the magnitude of 21.5 MPa, with the trend of 166°.

Jan 1, 2015