Qi Liu's research while affiliated with University of Alberta and other places

Publications (177)

Article
The effects of residual bitumen on oil sands tailings filtration have rarely been examined. In the present work, the filtration of bitumen-coated minerals, including quartz, rutile, kaolinite, and montmorillonite, was studied. Bitumen-coated quartz was compared with silanized quartz to decouple the effects of surface hydrophobicity and adsorbed bit...
Article
Separation of fine particles suspended in liquid is crucial yet difficult and inefficient in various engineering processes. In the oil sands industry, high fine solids content in produced bitumen is one of the hurdles preventing non-aqueous extraction (NAE) from being used in commercial operations. This work proposed a novel method for fine solids...
Article
Frozen oil sands adhere to the walls of mining fleets in winter, which is an undesirable phenomenon that reduces the delivery capacity of vehicles and wastes fuel for in-land transportation. For automated surface mining, an effective and scalable approach is needed to replace the current method for removing adhered oil sands by shovelling or steam...
Article
The flocculation behaviors of quartz using a dual polymer system containing tannic acid (TAN) and poly(ethylene oxide) (PEO) were investigated in this study, with dynamic floc size monitoring by the in-situ focused beam reflectance measurement technique. Variables of concern and their influence on the flocculation process were investigated from bot...
Article
Full-text available
The dewatering of oil sands tailings is one of the most challenging problems faced by the oil sands industry. Despite significant efforts in the past several decades, the industry still lacks viable technologies that can quickly dewater and reclaim the oil sands tailings and eliminate their environmental impacts. The poor dewatering of oil sands ta...
Preprint
Oil sands adhered on truck bed reduce transport capacity of the truck, require manual cleaning, and create hurdles for automated surface mining. Study on the adhesion properties of oil sands to solid substrates is important to minimize the fouling of substrates during mining operation. In this work, we study the influence of hydrophobicity and mech...
Article
A controlled study was carried out in this work to decouple the effects of the hydrocarbon chains and the type of hydrophilic groups of the collectors on their collecting ability for minerals with different particle sizes. A high purity niobium oxide (pyrochlore) sample, with two different sizes (medium size of 64 µm and 16 µm, respectively), were...
Article
Hypothesis It is hypothesized that grafting zwitterionic nanohydrogel (ZNG) helps to achieve anti-asphaltene properties on cellulosic substrates, thus overcoming the fouling issue of natural cellulosic materials for treating oily emulsions. It is also hypothesized that ZNG coatings enhance the water-binding affinity of the substrates, resulting in...
Article
Oil contaminations have been challenging issues in a wide range of engineering and environmental fields. Herein, we employ a small silane molecule, γ-mercaptopropyldi(trimethylsiloxy)methylsilane (MD(SH)M), to functionalize fiber-based substrates (i.e., stainless steel mesh, cotton fiber) for oil decontamination processes including oil-water separa...
Article
Oil fouling is commonly encountered in many environmental and engineering fields and remains a challenging issue. The fouling issue in steam-assisted gravity drainage (SAGD) process for extracting bitumen from oil sands deposits has received much attention from oil industry. In view of low capital investment and exceptional antifouling performance,...
Article
A high purity kaolinite sample was coated by bitumen, asphaltene, or maltene, and the charge characteristics of the coated kaolinite samples were studied by electrodeposition from their cyclohexane suspensions. The deposited films on both anodes and cathodes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectro...
Article
Efficient recycling of high-value metals from spent cathode materials is important in that it not only alleviates the severe shortage of raw material supply but also addresses the environmental and safety issues associated with the disposal of these materials. Here, we report a selective leaching strategy by virtue of the defect-induced lattice ins...
Article
Full-text available
Variables of hydrodynamics are equally important as those of surface chemistry in determining the efficiency of froth flotation processes. In a mechanical flotation cell, macro hydrodynamics is responsible for solids suspension and aggregates transport, and micro-turbulence plays an important role in the sub-processes of flotation, such as gas disp...
Preprint
Adhesion of frozen granular materials on solid surfaces creates various problems for surface cleaning, reduces the carrying capacity of vehicles, and increases energy consumption for in-land transportation. Here we report that water content determines the adhesion strength of oil sands on solid surfaces at temperature of -2.5 ◦C to -20 ◦C. Our meas...
Preprint
Adhesion of frozen granular materials on solid surfaces creates various problems for surface cleaning, reduces the carrying capacity of vehicles, and increases energy consumption for in-land transportation. Here we report that water content determines the adhesion strength of oil sands on solid surfaces at temperature of -2.5 ◦C to -20 ◦C. Our meas...
Article
As water-based extraction technologies for producing bitumen from oil sands have received increasing environmental concerns, developing non-aqueous extraction (NAE) technique is of both fundamental and practical importance. However, the relatively high concentration of fine solids trapped in the extracted bitumen presents an obstacle for pipeline t...
Article
Fine and ultrafine hydrophilic particles are typically left in a dispersed state in a flotation pulp when novel fine mineral flotation technologies are developed. These dispersed fine and ultrafine gangue particles can enter into flotation concentrate by mechanical entrainment, lowering concentrate grade. The problem is becoming increasingly more p...
Article
As non-renewable natural resources, minerals are essential in a broad range of biological and technological applications. The surface interactions of mineral particles with other objects (e.g., solids, bubbles, reagents) in aqueous suspensions play a critical role in mediating many interfacial phenomena involved in mineral flotation. In this work,...
Article
Mechanical entrainment of −10 μm gangue particles affects flotation selectivity and dilutes concentrate grade in fine minerals flotation. This study investigated the effect of aggregation/dispersion behaviors of fine hydrophilic particles on their entrainment in batch flotation using quartz and hematite as model minerals. Two structurally similar p...
Article
Full-text available
In this study, the effect of carbon dioxide in assisting paraffinic bitumen froth treatment was investigated. The work was divided into two parts, the effect of water addition on CO2-assisted asphaltene precipitation from a dry and clean bitumen sample by n-heptane and the effect of CO2 injection to a mixture of n-heptane and a commercial bitumen f...
Article
Starch was used as a selective depressant/flocculant for ultra-fine hematite, and polyethylene oxide (PEO) was used as a flocculant for ultra-fine quartz in the reverse cationic flotation of ultra-fine hematite-quartz mixtures. Batch flotation, sedimentation, focused beam reflectance measurement (FBRM) and scanning electron microscopic (SEM) measur...
Article
Emulsions frequently encountered in petroleum production, include water-in-oil (W/O) emulsions, oil-in-water (O/W) emulsions, and water-in-oil-in-water (W/O/W) emulsions, which considerably increase operation and production costs and cause technical challenges such as fouling and corrosion. Chemical treatment as a primary method has been extensivel...
Article
Facilitated transport membranes have been extensively applied in a myriad of industrial fields, in view of their distinctive capabilities of selective separation of target species (e.g., ions/small molecules). Despite much progress, it remains challenging to tackle the trade-off relationship between the stability and separation efficiency of these...
Article
Full-text available
Non-aqueous extraction (NAE) of bitumen from oil sands has been gaining great attention from both the industry and aca-demia as an alternative to the water-based extraction. A fine solids removal step is important for a NAE process in order to obtain high-quality bitumen product, which, however, remains a great challenge to reduce the fine solids c...
Article
Slop oil, a complex mixture of oil, water and fine solids, is extensively produced during exploration, production, and refining processes in oil and gas industry, which is undesired and has been a challenging issue. For example, steam-assisted gravity drainage (SAGD) is an effective technology for exploiting oil sands deposits. It provides a sustai...
Article
Decreasing fine mineral solids content in bitumen product generated from non-aqueous extraction (NAE) of oil sands is an important requirement to ensure that the product quality meets the downstream process requirements. Two approaches may be used, one is to remove the fine solids from bitumen product after NAE extraction, and the other is to try t...
Article
Flotation of fine mineral particles is one of the major challenges faced by the minerals industries worldwide. Flocculation of these fine particles prior to flotation, to form separate hydrophobic and hydrophilic flocs, is one of the methods to tackle this challenge. In order to gain a better understanding of the properties of hydrophilic polymer f...
Article
Entrainment is a process by which fine and ultrafine particles are transferred to the flotation froth from the top of the flotation pulp, and eventually discharge to the concentrate product, even when they are not attached to gas bubbles. Therefore, entrainment can be considered as a two-step process, one at the upper layer of the pulp to the flota...
Article
Full-text available
Bitumen froth generated from water-based extraction of Alberta oil sands typically consists of 60 wt% bitumen, 30 wt% water and 10 wt% mineral solids. The froth has to be cleaned by removing the mineral solids and water before it can be upgraded or sold directly to market. Currently, naphthenic or paraffinic froth treatment processes (NFT or PFT) a...
Article
This paper reports the effect of the molecular weight of polyacrylic acid (PAA) on the flocculation of sub-micron titanium dioxide particles. The average molecular weight (MW) of the three studied PAAs were 140,000, 512,000 and 1,483,000 g/mol, respectively. The flocculation process was studied by several techniques including focused beam reflectan...
Article
This paper reports the results of a study on the effect of particle size on the flocculation of ultrafine titanium dioxide (TiO2) by polyacrylic acid. Three TiO2 samples of a narrow size distribution, with median size at 38, 186 and 357 nm, respectively, were used in this work. The flocculation process was monitored in real-time by focused beam ref...
Article
Polymer inclusion membrane (PIM) has been progressively utilised in various chemical engineering applications. Understanding the interfacial interactions between PIM surface and surrounding solutions is significantly important for the industrial application of PIM systems. In this work, interfacial behavior of the PIM was studied during Zn(II) extr...
Article
Removing fine solids suspended in aqueous or oil media is crucial in many chemical, petroleum and environmental engineering processes with ever-increasing demands on improving product quality and meeting waste management standard. In oil industry, the removal of fine mineral solids is required to achieve high-quality oil products but remains a grea...
Article
Slime coating is a considerable problem in the flotation of coal. Although many works have been done, there are still some problems that have not been clarified. In this work, the subtle behaviors of montmorillonite coating on coal surface under finely divided slurry pHs (from 2.7 to 10.6) were studied systematically through micro-flotation test, z...
Article
Chemical functionalization of metal sulfides by adsorption of specially designed ligands is of primary importance in efficiently manipulating the physicochemical properties of the target surface. Despite the widely studied ligand–metal molecular systems and the generally used binding energy concept, reports on the bond character of ligand–metal sul...
Article
Full-text available
Talc is one of the most problematic hydrophobic gangue minerals that occur in sulfide ores such as molybdenite and Pt-bearing nickel sulfide ores. Owing to its strong natural hydrophobicity, talc can easily float into the sulfide mineral concentrates, which not only lowers concentrate grade but also adversely affects subsequent smelting. Over the p...
Article
Emulsions stabilized with asphaltenes are undesirable in oil production due to the challenges associated with fouling, corrosion and environment contaminations. To understand the stabilization mechanism, the interfacial behavior and interaction mechanism of pentol/water interface in the presence of asphaltenes were investigated by interfacial tensi...
Article
Full-text available
Billions of tones of thick waste streams with highly concentrated colloidal suspensions from different origins have been accumulated worldwide, exampled as over 220 km2 mature fine tailings (MFT) from oil sands production in north Alberta. Current treatment technologies are limited by slow yet insufficient water release and sludge consolidation. He...
Article
O-Carboxymethyl chitosan (O-CMC), a nontoxic and biodegradable derivative of the natural polysaccharide−chitosan, was recently found to be a viable alternative for the toxic depressants used in the flotation separation of chalcopyrite and molybdenite. In this work, the adsorption characteristics of O-CMC on molybdenite/chalcopyrite surfaces and the...
Preprint
The adsorption of humic acids on thiol-functionalized gold surfaces with varying hydrophobicity under different solution conditions, was investigated by quartz crystal microbalance with dissipation (QCM-D) and contact angle measurements. </div
Article
Considerable amounts of fine solids retained in the bitumen product have been a challenging issue impeding the industrial application of the non-aqueous extraction (NAE) of oil sands ore. The undesired stable suspension of bitumen-coated fine solids in the bitumen-solvent mixture is generally considered as the origin of solid migration to the NAE b...
Article
The flotation of pyrochlore using two common oxide collectors, octyl hydroxamic acid (OHA) and sodium oleate (NaOl), was studied by microflotation tests on high purity pyrochlore sample and batch flotation tests on a pyrochlore ore sample. The high purity pyrochlore sample was screened into different size fractions, −20 µm, −38 + 20 µm, −75 + 38 µm...
Article
Chemical functionalization of metal sulfides plays a critical role in many fields such as materials science and froth flotation. The commonly used thiol-bearing functionalization ligands are generally considered to bind with metal sulfides covalently, and the computational binding energy is widely used to evaluate the functionality of the ligands t...
Article
Full-text available
The flotation separation of molybdenite from copper sulfide minerals (mostly chalcopyrite) typically relies on the use of toxic inorganic depressants such as cyanides and sodium sulfide/hydrosulfide. In this work, a nontoxic, biodegradable and cost-effective derivative of the natural polysaccharide chitosan, O-Carboxymethyl chitosan (O-CMC), is inv...
Article
Full-text available
Humic acids (HA), a major component of humus or soil, was explored as a selective depressant for molybdenite during the flotation separation of molybdenite and chalcopyrite. Microflotation tests on single minerals revealed that chalcopyrite flotation was not affected by HA from pH 3 to 11, while molybdenite was strongly depressed by HA in the same...
Article
Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al2O3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an...
Article
The aim of the present work is to identify the most important species affecting a non‐aqueous bitumen extraction process and bitumen quality. This investigation was carried out on four petrologic end member samples from Syncrude's North Mine collected in 2012 (NM12), i.e., marine claystone (MC), marine sand (MS), estuarine claystone (EC), and estua...
Article
The objective of this study was to identify various mechanisms responsible for the poor flotation of a high-clay-content gold ore and then develop a remedial solution. Compared to the flotation of a clean gold ore with a low clay content, obtained from the same flotation plant, the flotation of the high-clay-content gold ore produced much lower gol...
Article
In this study, entrainment monitoring algorithms were developed, trained and implemented on the batch flotation of three synthetic mixtures of galena and quartz with different particle size ranges for the quartz mineral. An online image-based soft sensor framework was developed to estimate product grade and recovery using support vector regression....
Article
Deoiling enjoys great significance in recycling and landfill of spent hydrotreating (HDT) catalyst. In this study, a novel approach for oil removal from spent HDT catalyst with assistance of ultrasound was developed. The effects of variables on oil removal were investigated by response surface methodology and central composite design method. The oi...
Article
Complex sulfide ores are difficult to process and often require multi-stage sequential flotation. Process outputs such as grade and recovery in each stage are affected by various sub-processes in the system, and it is crucial to monitor the performance in order to maximize the production. In this work, we have proposed and implemented a dynamic mon...
Article
Full-text available
The anisotropic surface characteristics and interaction mechanisms of molybdenite (MoS2) basal and edge planes have attracted much research interest in many interfacial processes such as froth flotation. In this work, the adsorption of a polymer depressant [i.e., carboxymethyl cellulose (CMC)] on both MoS2 basal and edge surfaces as well as their i...
Article
Hydrophobic (HB) interaction plays a critical role in many colloidal and interfacial phenomena, biophysical and industrial processes. Surface hydrophobicity, characterized by water contact angle, is generally believed as the most dominant parameter determining HB interaction. In this work, we quantified the HB interactions of air bubbles and a seri...
Article
Hydrophobic (HB) interaction plays a critical role in many colloidal and interfacial phenomena, biophysical and industrial processes. Surface hydrophobicity, characterized by water contact angle, is generally believed as the most dominant parameter determining HB interaction. In this work, we quantified the HB interactions of air bubbles and a seri...
Article
Froth flotation has been widely used to separate sulfide minerals from sulfide ores, where the oxygen reduction reaction (ORR) plays a significant role as the cathodic reaction. However, the intrinsic ORR mechanism over sulfide minerals and its effect on the flotation performance remain unclear. Herein, we explored the intrinsic ORR mechanism over...
Article
The effects of non-polar oil on hydrophobic flocculation and micro-flotation of fine hematite (−20 µm) were studied when sodium oleate, octyl hydroxamic acid, or oleoyl hydroxamic acid was used as a collector. The micro-flotation test was carried out under neutral pH, and kerosene was used as the non-polar oil. Focused Beam Reflectance Measurement...
Cover Page
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Density functional theory (DFT) calculations reveal that the improved catalytic activity over the ultrathin 5-fold twinned Ag NWs originates from the increased ratio of the catalytically active sites contributed by both diameter and length effects, and the special 5-fold twinned nanostructure completely enclosed by energetically favorable facets fo...
Article
Owing to the increasing popularity of using waste disposal as a source material, inorganic salts such as CaCl2 and MgCl2 are frequently present in geopolymerization typically taking place in alkali media. Such contaminants influence the dissolution of the aluminosilicate source materials and consequently the properties of the geopolymers made. This...
Article
Extraction from oil sands is a crucial step in the industrial recovery of bitumen. It is challenging to obtain online measurements of process outputs such as bitumen grade and recovery. Online measurements are a prerequisite for innovating better process control solutions for process efficiency and cost reduction. We have developed a soft sensor to...
Article
Electroreduction of CO2 holds the promise for the utilization of CO2 and the storage of intermittent renewable energy. The development of efficient catalysts for effectively converting CO2 to fuels has never been more imperative. Herein, we successfully synthesized Ag2S nanowires (NWs) dominating at the facet of (121) using a modified facile one-st...
Article
Electrochemical reduction of CO2 (CO2RR) holds the potential to battle the greenhouse effect through the synthesis of carbon-neutral fuels. The high efficiency of noble metal catalysts for CO2RR is, therefore, highly desirable to reduce the quantities of noble metals. We herein synthesized 5-fold twinned Ag nanowires (NWs) with diameters less than...
Article
Full-text available
Humic acid (HA) has been studied as a potential selective depressant for molybdenite in the flotation separation of molybdenite and talc in this paper. In the single mineral flotation tests, HA has shown good depression ability to molybdenite over the entire pH range tested from pH 3-11, while the floatability of talc was only affected by HA under...
Article
Point defects, particularly vacancies, exist abundantly in the structure of a variety of clay minerals (e.g., kaolinite). Such defects significantly alter the physical/chemical characteristics of the minerals. Dissolution of kaolinite in an alkali medium is a critical step in the geopolymerization process and it determines the properties of the fin...
Article
The geopolymerization process involves the dissolution of aluminosilicates in an alkali solution followed by the polymerization of the dissolved aluminate and silicate oligomers to form an amorphous geopolymer. It is generally accepted that the dissolution determines the nature of the oligomers formed, thereby the properties of the resultant geopol...
Article
Full-text available
Surface interactions involving deformable air bubbles have attracted tremendous interest in a wide range of engineering applications, such as mineral flotation and bitumen extraction. In this work, for the first time, the interaction forces between air bubbles and bitumen surfaces in complex aqueous media of varying pH, salinity and salts were dire...
Article
The interactions between fine and coarse hematite particles were investigated, and their effects on the flotation of the hematite using sodium oleate as a collector were studied through micro-flotation tests, supplemented by optical microscopic analysis, extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theoretical analysis, and focused beam reflec...
Article
The current research was performed on four petrologic end members samples from Syncrude's North Mine collected in 2012 (NM12), i.e. marine clay (MC), marine sand (MS), estuarine clay (EC), and estuarine sand (ES). The mineralogical compositions of the four petrological end members were determined using X‐ray diffraction (XRD), quantitative XRD (QXR...
Article
Slime coating is a significant phenomenon in froth flotation. The adverse effects of slime coating, by which a value mineral is covered by slimes and prevented from direct contact with collectors and/or air bubbles, have been recognized for decades. It happens ubiquitously in the flotation of various minerals, including sulfide minerals (sphalerite...
Article
The mineralogy, chemistry, surface properties and pore structure characteristics of the four different petrologic types of Alberta oil sands were determined in order to better understand their impact on non-aqueous solvent bitumen extraction. Quartz, clay minerals and carbonates were the main mineral constituents of the studied samples. With increa...