The Porosity, Permeability and Restructuring of Heterogeneous Filter Cakes

2010 ◽  
Vol 33 (8) ◽  
pp. 1283-1289 ◽  
Author(s):  
K. Chellappah ◽  
E. S. Tarleton ◽  
R. J. Wakeman
Keyword(s):  
Filter Cakes

scholarly journals The Influence of Surface Energy on the Washing Quality of Filter Cakes

2011 ◽  
Vol 01 (04) ◽  
pp. 252-255 ◽  
Author(s):  
Markus Wilkens ◽  
Urs A. Peuker
Keyword(s):  
Surface Energy ◽  
Filter Cakes

Zusammensetzung des Filterkuchens an Schlitzwandlamellen mit kurzer und langer Standzeit/Composition of filter cakes arising during slurry wall construction depending on duration of suspension supported period

Bauingenieur ◽  
2015 ◽  
Vol 90 (02) ◽  
pp. 63-70
Author(s):  
Diethard König ◽  
Thomas Schröder
Keyword(s):  
Slurry Wall ◽  
Wall Construction ◽  
Filter Cakes

Bei der Herstellung von Schlitzwänden im Zweiphasenverfahren ergeben sich aus baubetrieblichen Gründen immer wieder Situationen, in denen Schlitze suspensionsgestützt lange stehen bleiben, bevor mit dem Betoniervorgang begonnen werden kann. Es herrscht die Vorstellung, dass sich mit zunehmender Standzeit unter Flüssigkeitsstützung der Filterkuchen an der Schlitzwandung, welcher später zwischen der fertig betonierten Wand und dem Boden verbleibt, verstärkt ausbildet und reibungsmindernde Eigenschaften hat. Aus dieser Annahme heraus wird in den Regelwerken verlangt, dass der Wandreibungswinkel für die statische Berechnung der Schlitzwand bei planmäßig langen Standzeiten des suspensionsgestützten Schlitzes von mehr als 30 Stunden mit k = 0 anzusetzen ist. Bleibt die Standzeit des suspensionsgestützten Schlitzes dagegen unter 30 Stunden, ist je nach Beschaffenheit des Bodens ein Ansatz des Wandreibungswinkels ohne weiteren Nachweis von bis zu k = ½ ‘k möglich.   In diesem Beitrag werden Untersuchungen an Filterkuchenmaterial vorgestellt, das bei einer laufenden Baumaßnahme an zwei Schlitzwandlamellen gewonnen wurde. Diese Lamellen unterscheiden sich bei sonst gleichen Randbedingungen durch unterschiedlich lange Standzeiten des suspensionsgestützten Schlitzes (16 Stunden, 70 Stunden). Die Untersuchungen zeigen, dass sich bei den anstehenden Verhältnissen infolge der längeren Standzeit keine signifikanten Änderungen in der Ausbildung und in der Zusammensetzung des Filterkuchens ergeben.

Formation of Filter Cakes and Precoats

1975 ◽  
pp. 297-314
Author(s):  
P. M. Heertjes
Keyword(s):  
Filter Cakes

In Situ Examination of Effects of Pressure Differential on Compressible Cake Filtration

1990 ◽  
Vol 22 (12) ◽  
pp. 125-134 ◽  
Author(s):  
B. R. Bierck ◽  
R. I. Dick
Keyword(s):  
Activated Sludge ◽  
Pressure Differential ◽  
Filter Medium ◽  
Cake Filtration ◽  
Solids Concentration ◽  
Cake Formation ◽  
Thin Skin ◽  
Production Behavior ◽  
Concentration Changes ◽  
Filter Cakes

A synchrotron X-ray absorbance technique was used to monitor suspended solids concentration changes in compressible filter cakes formed at different constant pressure differentials. Results for a kaolin slurry and an activated sludge manifested the markedly higher compressibility of the latter sludge. A model developed to describe effects of pressure differential on filtrate production behavior of an ideal compressible slurry indicated that the kaolin slurry behaved as such. However, the activated sludge was not ideal because changes in pressure differential did not cause the idealized change in filtrate production rate. A thin skin of activated sludge solids at the filter medium accounted for the non-ideal compressive behavior. Porewater pressure data acquired 0.86 mm above the filter medium during activated sludge filtration provided evidence of skin formation and its effect - virtually the total pressure drop occurred within this 0.86 mm region throughout cake formation (after which shrinkage began). Hence, significant effective stresses required to consolidate the sludge cake did not develop in most of the cake until cake formation was complete and shrinkage began.

Separation of Cu and As in Cu-As-containing filter cakes by Cu 2+ -assisted acid leaching

2017 ◽  
Vol 172 ◽  
pp. 45-50 ◽  
Author(s):  
Yong Ke ◽  
Chen Shen ◽  
Xiao-Bo Min ◽  
Mei-Qing Shi ◽  
Li-Yuan Chai
Keyword(s):  
Acid Leaching ◽  
Filter Cakes

Investigation of the Effect of Mechanical Mixing on Dewatering of Fine Coal Vacuum Filter Cakes

2000 ◽  
Vol 21 (2) ◽  
pp. 177-195 ◽  
Author(s):  
F. S. BOURGEOIS ◽  
M. T. HAQUE
Keyword(s):  
Vacuum Filter ◽  
Mechanical Mixing ◽  
Fine Coal ◽  
Filter Cakes

Chemically Improved Filter Cakes for Drilling Wells

2002 ◽  
Vol 124 (4) ◽  
pp. 223-230 ◽  
Author(s):  
Neeraj S. Nandurdikar ◽  
Nicholas E. Takach ◽  
Stefan Z. Miska
Keyword(s):  
Drilling Fluid ◽  
Structural Features ◽  
Environmental Scanning ◽  
Drilling Fluids ◽  
Novel Device ◽  
Chemical Reagents ◽  
High Pressure High Temperature ◽  
Filtration Apparatus ◽  
Filtration Properties ◽  
Filter Cakes

Blast furnace slag (BFS) is a latent hydraulic material similar in composition to Portland cement. BFS was originally studied for mud to cement (MTC) purposes. This application called for large quantities of BFS (40–500 ppb (lb/bbl)) and ultimately proved to be ineffective. Subsequently, BFS has been investigated as an additive in drilling fluids. In a recent study, muds containing additive-level concentrations (5–30 lb/bbl) of BFS were shown to be effective in reducing formation damage. The present work extends the investigation of BFS as a drilling fluid additive. Specifically, we have explored the use of chemical reagents to activate the BFS in filter cakes to achieve cakes that are thin, impervious and firm. Filter cakes were formed from slag-laden drilling fluids in a high-pressure, high-temperature reverse filtration apparatus (permeability plugging apparatus). Studies were conducted with partially hydrolyzed polyacrlyamide (PHPA) muds and CaCO3-based fluids containing different loadings of BFS. Filter cakes of these fluids were treated with several different activators and the results were compared to cakes containing no BFS. Different activation techniques were investigated and a novel device was designed to measure the strength of the filter cakes. An environmental scanning electron microscope examined the relationship between the structural features of the activated cakes and their strengths. This study demonstrates that filter cakes containing BFS can be chemically activated to produce thin, firm cakes with improved filtration properties. These cakes should be able to form better bonds with cement subsequently used for completion.

Laboratory Investigation of Brine Diffusion Through Oil-Based Mud Filter Cakes

2010 ◽  
Author(s):  
Andreas Nicolas Berntsen ◽  
Anne-Sophie Robbes ◽  
Pierre Rolf Cerasi ◽  
Claas H. Van Der Zwaag
Keyword(s):  
Laboratory Investigation ◽  
Filter Cakes
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