Shear zones

When an impeller is rotated in an agitated tank containing two immiscible Hquids, two processes take place. One consists of breakup of dispersed drops due to shearing near the impeller, and the other is coalescence of drops as they move to low shear zones. The drop size distribution (DSD) is decided when the two competing processes are in balance. During the transition, the DSD curve shifts to the left with time, as shown in Figure 18. Time required to reach the equiHbrium DSD depends on system properties and can sometimes be longer than the process time. 

High-Intensity Mixer. Mixers such as that shown in Fig. 18-44 combine a high shear zone with a fluidized vortex mixing action. Blades at the bottom of the vessel scoop the batch upward at peripheral speeds of about 40 m/s (130 ft/s). The high shear stress (to 20,000 s" ) and blade impact easily reduce agglomerates and aid intimate dispersion. Since the energy input is high [200 kW/m (about 8 hp/fE)h even powdery material is heated rapidly. 

Two-Roll Mills These mills contain two parallel rolls mounted in a heavy frame with provision for accurately regulating the pressure and distance between the rolls. As one pass between the rolls does little blending and only a small amount of work, the mills are practically always used as batch mixers. Only a small amount of material is in the high-shear zone at any one time. 

The time required to pass through the high shear zone will be proportional to the volume of the vessel divided by the flow from the turbine. This will be porportional to 1/ND. With a turbine in turbulent flow, turnover is relatively rapid and all the fluid will pass through the impeller region in a relatively short period of time. The flow regime in an anchor or helically agitated vessel can be inferred from the flow studies by Smith and Peters (], 13j. These indicated... 

A dimensionless dispersion number, based on the probable number of passes through the shear zone for an ingredient to be dispersed, was developed for scale-up of mixing of short fiber... 

Lallemand and Jolivet (1986) have interpreted the opening of the Japan Sea as a pull-apart basin between two right-lateral strike-slip fault zones the Yagsan-Tsushima fault to the west and the Tartary-Hidaka shear zone to the east. 

For any given size of mill there is a minimum volume of polymer per unit width of roll, below which no dispersive mixing occurs. Increasing the amount of material above this minimum level increases the high shear zone in the polymer, increasing dispersive mixing. There is an upper limit however, above which a circulatory flow develops at the entrance to the nip region and no further improvement occurs. 

KEYWORDS indicator minerals, sphalerite, galena, Great Slave Lake Shear Zone... 

The uppermost bedrock in northwest Alberta consists of a Cretaceous succession of nearly horizontal and poorly-indurated marine shales of the Fort St. John Group (Loon River and Shaftesbury formations) and Smoky Group, separated by deltaic to marine sandstones of the Dunvegan Formation (Okulitch 2006). A large structural feature, the Great Slave Lake Shear Zone (GSLSZ) cuts across the study area (Eaton Hope 2003). 

Eaton, D.W. Hope, J. 2003. Structure of the crust and upper mantle of the Great Slave Lake shear zone, northwestern Canada, from teleseismic analysis and gravity modelling. Canadian Journal of Earth Sciences, 40, 1203-1218. 

Mineralization was represented by quartz-chlorite-carbonate-sulfide veins with visible chalcopyrite, galena, sphalerite, pyrrhotite, cobaltite, limonite and malachite. Fractures filled by veins are identified on aerial photos as one submeridional zone up to 20 m thick and 500 m long. The northeastern linear system represented by a shear zone containing veinlets with arsenopyrite, bismuthine, gold and silver sulfosalts. Twelve veins that differ in extent and intensity of mineralization were discovered, with some veins yielding 3 wt. % Sn, 3 wt. % Cu, and up to 250 g/t Ag. 

The >7 Moz Morila Au deposit, Mali, is an enigmatic member of a continuum of Au deposits now described across the West African Craton (Fig. 1). In contrast to more traditional shear zone-hosted and stockwork deposits, hydrothermal alteration and brittle structures at Morila are cryptic and there are no apparent lithological controls on mineralization. 

The Brunswick Subduction Complex (BSC) is best know as the host sequence to world class, syngenetic volcanogenic massive sulfide deposits of the Bathurst Mining Camp (BMC) hosting deposits such as the giant Brunswick No. 12 VMS deposit (>300 Mt of massive sulfides). Less well known are the syntectonic, precious-metal breccia and (or) vein deposits/occurrences in the BSC. The shear zone-hosted Middle River gold deposit (MRG) is the most significant of these and has returned assays of up to 7.44 g/t Au over 6.5 m (DDH MR-05-06). 

Ar- Ar geochronological constraints of the ore-bearing ductile shear zones at Hukeng tunsten deposit, Jiangxi Province... 

Keywords Quartzs-veins-type tungsten deposit banded structure ductile shear zone °Ar- Ar dating Hukeng, Jiangxi... 

Fig. 2. The step heating Ar-Ar plateau age (A), isochron age (B), and inverse isochron age (C) for sericite folia from mylonite of the EW-trending ductile shear zone.

Comparing the kinematic characteristics of the ductile shear zone and main fault zone in the mining area, there is a genetic relationship. Field mapping reveals that there was another intrusive episode after the ore-bearing granite was emplaced. It... 

The Tisdale rocks were deformed by two tectonic events that resulted in superposition of east-west isoclinal folds on older north-south open folds. Five camp- to regional-scale faults, including the Hollinger Shear Zone (HSZ), have offset all these rocks. The HSZ is a reverse fault ( 140 m offset) that passes through the Hollinger-Mcintyre mine, strikes 57°, dips 65°S, extends to a depth of >1,500m and formed synchronous with the east-west folds. Most gold mineralization in the HMC deposit is associated with rocks in and above the HSZ. 

Fig. 1. Location map of the Cage District in northern Quebec within the Core Zone of the Churchiii Province. KSZ-Komaktorvik Shear Zone GRSZ-George River Shear Zone NPS-Nain Piutonic Suite DPB-De Pas Bathoiith BD-Burweii Domain LLC-Lac Lomier Compiex (modified from Wardie et at. 2002).

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