Flotation Costs Research Articles

A new insight on a novel auxiliary collector 4-MBA synergize with BHA to enhance flotation of scheelite

The hydroxamic acid reagents are extremely pervasive in the collector of scheelite flotation. The high flotation cost is caused by its large dosage and high price. A novel auxiliary collector 4-methodybenzoicacid (4-MBA) was used in combination with benzohydroxamic acid (BHA) to optimize the flotation reagents system for scheelite in the study. A single 4-MBA has weak collection capacity for scheelite. Nevertheless, the combination of 4-MBA and BHA optimized the flotation system of scheelite by ensuring its recovery and reducing the reagent consumption. The results of solution surface tension and contact angle measurements showed that the surface tension of the mixed reagent solution is a relatively lower and the hydrophobicity of the scheelite surface is a relatively higher in the BHA and 4-MBA mixed reagent system. Additionally, a synergistic effect between BHA and 4-MBA on Pb2+ activated scheelite is revealed by the Zeta potential measurements, infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The addition of 4-MBA promoted the physical and chemical adsorption of BHA. The results of molecular dynamics simulation (MDS) further explained that the collector adsorption layer of the surface of scheelite (112) is more compact under BHA and 4-MBA mixed reagent system, which prevents the vertical entry of water phase and improves the hydrophobicity of scheelite. Finally, the bench-scale flotation experiment verified that the addition of 4-MBA enhanced scheelite flotation with BHA, and decrease the flotation cost of scheelite.

Effect of Prestirring Time on Carbon Removal from Coal Fly Ash in the Flotation Technology.

Coal fly ash (CFA) is one of the industrial byproducts of burning coal for energy production and has unburned carbon, which negatively affects its full potential use. The flotation technology can be effective in separating unburned carbon from CFA, and the prestirring time is crucial for the ideal initial conditions during the flotation process. To find the suitable prestirring time, eight prestirring times, including 0, 1, 2, 3, 4, 5, 6, and 7 min, were selected in this paper, followed by flotation of CFA after prestirring. Parameters such as loss on ignition (LOI), the removal rate of unburned carbon (RUC), contact angle, and particle size volume fraction were used to assess the effect of prestirring time on flotation results. The results showed that the prestirring time significantly affects the CFA flotation performance. As the prestirring time increased, the LOI of CFA first decreased and then increased, and the contact angle showed the opposite trend. Besides, the prestirring time of over 2 min positively affected the fineness of the tailings. Overall, the prestirring time of 3 min had the most significant carbon removal effect, obtaining an LOI of tailings of 0.96%, a yield of 74.56%, an RUC of 72.70%, and a volume fraction less than 45 μm of 36.65%. This study provides theoretical support for improving stirring efficiency and saving flotation costs in industrial applications and is conducive to the recycling of CFA resources.

Multinational Corporations and SEO Discounts

The fact that publicly traded companies incur substantial costs when issuing new equity has been extensively documented in the empirical finance literature. In particular, numerous studies show that seasoned equity offerings (SEOs) tend to be priced significantly below prevailing market prices, thereby causing issuers to leave money on the table. Offer price discounting is an indirect flotation cost borne by pre-SEO shareholders that, according to extant theoretical and empirical research, arises due to asymmetric information. A heretofore unrelated literature argues that corporate multinationalism, i.e., establishing operations in one or more foreign countries, exacerbates the asymmetric information problem via greater costs to shareholders of monitoring the activities and performance of foreign subsidiaries. Motivated by these lines of thought, I investigate the relation between SEO discounting and corporate multinationalism. Using a sample of SEOs completed by U.S. firms between 1998 and 2016, I show that offer price discounting is significantly higher in offerings conducted by multinational firms relative to those conducted by purely domestic firms after controlling for known determinants of SEO discounts. This effect is stronger for multinational firms with foreign subsidiaries spread across a greater number of countries and weaker for multinationals that hire a high-reputation underwriter to lead the underwriting syndicate. These findings suggest that asymmetric information costs borne by seasoned equity issuers are increasing in the geographic scope of a firm’s operations, which can be mitigated by certification from a highly reputed lead underwriter.

Is it possible to efficiently and sustainably remove microplastics from sediments using froth flotation?

Microplastics (MPs) contamination in sediments is becoming an intractable environmental issue. Numerous methods are proposed for removing microplastics from aqueous solution, however, the techniques developed for microplastic removal from sediments have been rarely reported. To target the dilemma, this work innovatively applied froth flotation to the MPs removal from beach and lake sediments. Interestingly, we found that the sediment particle adhered to the MPs surfaces resulted in unavailable attachment of air bubbles to MPs surfaces. The effects of pH, salinity, moisture, MPs property, sediment type, and incubation time on MPs flotation were systematically investigated. According to characterization, polyvinyl chloride (PVC) was only covered by aluminosilicate, while acrylonitrile butadiene styrene (ABS) interacted with aluminosilicate and quartz. Analysis of Extended Derjaguin Landau Verwey Overbeek (EDLVO) further confirmed that the stronger electrostatic repulsion between PVC and sediment contributed to the higher energy barrier. However, sediment particles were easier to adhere to ABS with less negative surface potential. Besides, metal ions adsorbed on MPs surfaces might serve as a bridge to link MPs and sediment particles. To improve the flotation performance, a flotation process combined 10 g/ton of sodium oleate could achieve approximately 100% removal of MPs. To further evaluate the applicability of froth flotation, we conducted life cycle assessment (LCA) and economic assessment. Froth flotation outperformed other separation methods in all environment categories. The cost of froth flotation, mostly electricity, was much lower than other removal technologies. Overall, this work provided an effective and sustainable candidate for MPs removal from the sediment environment.

A novel renewable collector from waste fried oil and its application in coal combustion residuals decarbonization

A novel renewable collector was prepared by transesterification of waste fried oil (WFO), which was used to remove the unburned carbon in the coal combustion residuals (CCRs). The specific preparation process included purification, filtration, alkali catalysis, and oxidation (ozonization). Coal gasification ash (CGA) and coal fly ash (CFA) are the two main CCRs, and their properties were analyzed by XRD, SEM, FTIR and XPS. The results showed that most of CGA and CFA particles had rough surface and strongly hydrophilic surfaces owing to the existence of abundant oxygen-containing functional groups (35.93% and 66.95%, respectively). Waste fried oil collector (WFOC) was rich in oxygen-containing groups, which could be adsorbed onto carbonaceous matter surfaces to achieve hydrophobization. Ozonization could increase the content of oxygen-containing functional groups (CO, -C-O-C-, etc) in O3-WFOC. As the oxidation time increased, CGA and CFA had the same increasing trend of the flotation rate (fastly-slowly-fastly-slowly), and the better ozonization time was 2 h. This work demonstrated that WFOC/O3-WFOC could reduce the dependence on traditional collectors, cut down the flotation cost and solve the environmental problems caused by large amounts of CCRs and WFO by “waste control through waste”.

The choice of equity financing: Floating-priced warrants versus SEOs

A floating-priced warrant (FPW) is an American warrant with a resettable exercise price at a discount from the market price. FPWs are frequently issued by Japanese firms as an alternative equity financing method to seasoned equity offerings (SEOs). This study reveals what kind of firms prefer to issue FPWs rather than SEOs and why. The results reveal that issuers of FPWs are poor performers and have higher levels of information asymmetry compared to issuers of SEOs. Such firms will face higher flotation costs when issuing common stocks directly. However, the flotation costs of selling equity via FPWs are relatively fixed and irrelevant to the issuer's firm characteristics. Although the average flotation cost of FPWs is higher than that of SEOs, issuers of FPWs would face an even higher flotation cost had they conducted SEOs instead. The result supports the flotation cost minimization hypothesis as a motive for issuing FPWs.

Flotation costs of seasoned equity offerings: Does corporate social responsibility matter?

AbstractThis paper investigates the effect of corporate social responsibility (CSR) on flotation costs in seasoned equity offerings (SEOs). On the basis of an international sample covering 38 countries during the period 2002–2018, we find that CSR performance is negatively associated with SEO flotation costs and this negative impact is mainly attributable to issuers' engagement in CSR, particularly in environmental and social activities. We further reveal that the CSR strategies of SEO issuers are successful in reducing market‐based costs as well. Overall, this paper offers critical insights for understanding the role of stakeholder‐oriented practices in adding value to shareholders through equity offerings.

Investigation of Determinants of Direct Flotation Costs of Public Securities Offerings in Kenya

This study seeks to examine factors influencing direct flotation costs for public issuance of securities in Kenya’s capital markets since no benchmark exists that potential issuers can utilize for estimating flotation expenses. The research seeks to identify the quantum as well as understand the effects of offer size, offer method, underwriter (lead transaction advisor) reputation, market segment, offer complexity and firm size on flotation costs. Secondly, it seeks to develop a flotation cost function that can be applied to estimate direct flotation costs. Finally, it seeks to understand whether the flotation cost, certification and market power hypothesis are pertinent in Kenya’s securities markets. The study adopts a quantitative approach consisting of univariate analysis, as well as hypothesis testing using bivariate and multivariate regression, applied on a longitudinal panel dataset for public issues between 2007-2019. The study finds that the mean and trimmed mean for flotation cost as a percentage of offer size is 3.4% and 3.1% of offer size, with a median of 2.98% for the review period. The correlations show that offer size has the highest correlation to flotation cost with (0.610), followed by firm size at (0.521), offer complexity with (0.411), market segment at (0.246), underwriter experience with (0.175) and offer method with (-0.143). The results indicate all predictor variables have a positive correlation with flotation cost ranging from strong - weak except offer method with a weak negative correlation. The bivariate regression results indicate that offer size, firm size, offer complexity and market segment have significant influence on flotation costs for securities offerings. However, offer method and underwriter reputation have no significant influence on flotation costs. The regression results for the combined effect of the overall model are significant where p value is 0.000. This confirms that predictor variables in the model have a significant combined effect on flotation cost. The study also found clear evidence in favor of the economies of scale view and certification hypothesis.

Application of Magnetization Treatment in Flotation

With the decrease of mineral resources reserves, the characteristics of “poor, fine and miscellaneous” of mineral resources are becoming more and more obvious. People pay more and more attention to the environmental protection. A simple, green and efficient separation process magnetization flotation has been paid more and more attention by mineral processing workers. Based on the analysis and summary of the development process and advantages of magnetic flotation, the application status of magnetic flotation at home and abroad in the processing of ferrous metal ore, non-ferrous metal ore, rare metal ore, precious metal ore, non-metallic ore, coal, etc. Compared with conventional flotation, it is found that the cost of magnetic flotation is lower than that of conventional flotation. Combining theoretical analysis, computer simulation, experiment and advanced detection methods, the mechanism, influencing factors, process and equipment of magnetic flotation are the development trend in the future.

Effect of Capital Structure on Financial Performance of Oil and Gas Companies Quoted on the Nigerian Stock Exchange

This study aims to find the impression of capital structure on financial performance of oil and gas companies quoted on the Nigerian Stock Exchange (NSE). The primary objective is to find the connection between debt to total assets on return on assets and total debt to total equity on return on equity of oil and gas companies quoted on the Nigerian Stock Exchange. Secondary data were carefully sourced from the financial statement/annual reports of the oil and gas companies quoted on the Nigerian Stock Exchange. The data span from 2005 to 2018. E-views 10.0 software was used to analyse the data collected. Findings from data analysed show that total debt to total assets has no significant effect on return on assets of oil and gas companies quoted on the Nigerian Stock Exchange and that total debt to total equity has a significant effect on return on equity of oil and gas companies quoted on the Nigerian Stock Exchange. Accordingly, the study concluded that financial performance is independent of capital structure as companies prefer internal financing before resorting to any form of external funds because internal funds incur no flotation costs and require no additional disclosure of proprietary financial information that could lead to more severe market discipline and a possible loss of competitive advantage. It recommends that firm’s management should establish a debt-equity mix capable of improving return on assets notwithstanding the measurement of capital structure measure adopted and that oil and gas companies should fund their operations with more of equity capital as it significantly influence shareholders’ wealth.

Capability for metallurgical processing of Intermediate products for the processing of polymetallic ores

The copper smelting facilities of the Ural Mining and Metallurgical Company (UMMC) mostly rely on copper-zinc and polymetallic ores. Finely disseminated minerals are associated with increased cost of selective flotation and mineral losses with dissimilar concentrates. In selective flotation of copper-zinc ores from the Urals region, between 6% (high zinc ores) and 23–44% of zinc get lost with copper concentrates depending on metal concentration and intergrowth of minerals in the ore, with the concentration of zinc in it being less than 1 %. In metallurgical processing, 90–95% of zinc contained in copper concentrates go to waste with the slag. Processing of polymetallic ores from the Altay deposits is associated with high losses of copper, lead and zinc, which get lost with dissimilar concentrates. The authors of this paper propose to obtain bulk concentrates from low zinc (0.4–1% Zn) and highly complex copper-zinc ores; obtain high-quality zinc and polymetallic (copper-lead-zinc) concentrates from polymetallic ores; set up a processing facility for polymetallic concentrates at the Mednogorsk Copper-Sulphur Plant (MCSP) that would involve the following stages: matte and zinc slag smelting – matte converted to blister copper – copper extraction from and fuming of smelter and converter slags. The main smelting vessel is currently under reconstruction aimed at introducing high-pressure highly concentrated blast oxygen; a slag fuming complex will need to be built with gas scrubbers to produce lead-zinc sublimates. An existing oxygen plant is utilised, and all sulphur containing gases are treated in a sulphuric acid facility present at the site. The advantages of the proposed processing scheme include: increased end-to-end recovery (from complex ores to refined ingots): copper — by 2.7%, zinc — by 8.1%; the output of refined lead at UMMC increased by 14 th tons with no special investment made; simpler processing schemes and a significant reduction in processing and transportation costs; rational use of the MCSP production facilities and infrastructure, raw materials available on a stable and long-term basis; an increase of 3.8 bln rubles per annum in the commodity output of UMMC.

Waste colza oil used as renewable collector for low rank coal flotation

The high cost of low rank coal flotation using diesel as the collector significantly restricts the improvement in economic efficiency of the coal plant. Waste colza oil (WCO) from the catering industry was used as a renewable and alternative collector for ultrafine low rank coal flotation in this investigation. Scanning electron microscopy (SEM) test was carried out to check the surface morphologies of the coal sample. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) tests were performed to examine the coal chemical compositions. The flotation yield using WCO was always higher than that of using diesel, especially at a high dosage. When 6 kg/t dosage was used, 35.68% yield was obtained with WCO, 5.54% higher than that with diesel. The mechanism of WCO used as an alternative collector was discussed based on the induction time, FTIR, and XPS tests. The induction time of the low rank coal after conditioning with 6 kg/t diesel and WCO were 200 ms and 100 ms, respectively, indicating that WCO was a more effective collector for improving the floatability of low rank coal compared with traditional diesel. XPS tests confirmed the adsorption of WCO on coal surface as the WCO has a large amount of CO groups according to FTIR results. The hydrogen bonding between oxygen-containing groups in WCO and low rank coal surface was responsible for the improvement of floatability and flotation recovery.

How firms borrow in international bond markets

PurposeThis paper aims to investigate how firms from emerging economies choose among different international bond markets: global, US144A and Eurobond markets. The authors explore if the ranking in regulatory stringency –global bonds have the most stringent regulations and Eurobonds have the most lenient regulations – leads to a segmentation of borrowers.Design/methodology/approachThe authors use a novel data set from emerging economy firms, treating them as consolidated entities. The authors also obtain descriptive evidence and perform univariate non-parametric analyses, conditional and multinomial logit analyses to study firms’ marginal debt choice decisions.FindingsThe authors show that firms with poorer credit quality, less ability to absorb flotation costs and more informational asymmetries issue debt in US144A and Eurobond markets. On the contrary, firms issuing global bonds – subject to full Securities and Exchange Commission requirements – are financially sounder and larger. This exercise also shows that following the global crisis, firms from emerging economies are more likely to tap less regulated debt markets.Originality/valueThis is, to the authors’ knowledge, the first study that examines if the ranking in stringency of regulation – global bonds have the most stringent regulations and Eurobonds have the most lenient regulations – is consistent with an ordinal choice by firms. The authors also explore if this ranking is monotonic in all determinants or there are firm-specific features which make firms unlikely to borrow in a given market. Finally, the authors analyze if there are any changes in the debt-choice behavior of firms after the global financial crisis.

Effects of monohydric alcohols on the flotation of magnesite and dolomite by sodium oleate

Part of NaOL (sodium oleate) was replaced with different monohydric alcohols (butanol, hexanol, and octanol) in the flotation of magnesite and dolomite for lower flotation costs and higher flotation efficiency. Zeta potential analyses, contact angle measurements and molecular simulations were used to investigate mechanisms of the adsorption of alcohols. Single mineral flotation tests showed that combined reagents could produce better flotation results than single NaOL. Contact angles and zeta potentials of the two minerals indicated that alcohols were adsorbed on mineral surfaces physically and improved the hydrophobicity when combined with NaOL. Molecular dynamics simulation was used to explore mechanisms of alcohols at the molecular level. Different adsorption models indicated that alcohols could increase NaOL density and the thickness of the hydrophobic layer on both mineral surfaces. As a result, the flotation of magnesite and dolomite was enhanced. Based on molecular dynamics calculation, the adsorption mode of octanol on mineral surfaces, when combined with NaOL for flotation, was shown to be adsorbed through hydrogen bonds.

Reasons for Debt Specialization: Understanding the Perspectives of Small and Large Organizations

Debt specialization (DS) has become widespread among organizations in recent years. However, the reasons for its existence and prevalence have yet to be fully examined, especially among small and large firms. This paper aims to empirically determine whether both small and large companies pursue DS strategies for similar reasons. We use seven years’ panel data for 2009–15 for 419 nonfinancial companies in Pakistan, listed on the Pakistan Stock Exchange. The results of the comparative analysis confirm the existence of DS across organizations. Small firms follow DS to reduce expected bankruptcy costs, economize information asymmetries and decrease agency conflicts due to limited ingress to the debt market. Large companies include fewer types of debt to reduce operational risk and flotation costs and for building a good reputation. We suggest several theoretical justifications for these results, based on tradeoff and agency cost theory.

Reasons of Debt Specialization: Understanding the Perspectives of Small and Large Organizations

Debt specialization (DS) has become a wide spread phenomenon among organizations during the recent years, However, the reasons of DS among small and large organizations are yet to be fully known. This paper aims to empirically find whether small and large firms pursue DS strategy for similar reasons or for different one. By using 7 years’ panel data of 419 non-financial companies, the comparative results confirm the existence of DS across organizations. Small companies follow it to reduce expected bankruptcy cost, for economizing information asymmetry, decreasing agency conflicts and due to limited ingress to the debt market. While large companies include few types of debt to reduce operational risk, flotation cost and for building good reputation. We suggest several theoretical justifications for these results. The usage of short term debts is considerably important for all types of organizations irrespective of size.

How Firms Borrow in International Bond Markets: Securities Regulation and Market Segmentation

We investigate how firms in emerging economies choose among the different international bond markets: global, US144A and Eurobond markets. By exploiting the connection between the market of issuance and regulatory disclosure of information, we show that firms with poorer credit quality, less ability to absorb flotation costs and more informational asymmetries issue debt in US144A and Eurobond markets, where regulation is lighter and information is less public. On the contrary, firms issuing global bonds – subject to full SEC requirements – are financially sounder and larger. This exercise also shows that, following the global crisis, firms are more likely to tap less regulated debt markets. The results are supported by descriptive evidence, univariate non-parametric analyses, and conditional and multinomial logit analyses. To research the issue, we have constructed a novel data set containing information on firms’ debt securities issuance and their financial accounts for the period 2000-2014. To account for firms' complex structures, we look at the balance sheet of the guarantor of debt, which need not be the issuing company. The data set comprises 3,944 debt securities, guaranteed by firms of 36 emerging economies, which amount to a total of 1.2 USD trillion in debt issued.

Skewness Preference and Seasoned Equity Offers

We find that the degree of expected idiosyncratic skewness in seasoned equity issuers’ stock returns is an important determinant of flotation costs and subsequent abnormal stock performance. High skewness issuers incur significantly greater offer price discounts, particularly when institutional share allocation is largest, pay higher gross underwriting spreads, and exhibit poorer stock performance in the three years after issuance, all compared to low skewness issuers. These results suggest that skewness-induced overpricing increases the flotation costs of seasoned equity offers and leads to poor subsequent stock performance. Received November 18, 2014; accepted December 17, 2015 by Editor Paolo Fulghieri.

A Proposed Framework to Reduce Asymmetric Information in Equity Offerings

Abstract The security offering literature shows that firms offering their shares for sale to the public generally manage their earnings upwards around the offering to raise investor demand for the firm’s shares and increase their sale price. In addition, the literature demonstrates that earnings management around the offering increases the information asymmetry between the issuers and outside investors, thereby increasing the issue flotation costs. Markedly increased flotation costs imply, inter alia, a reduced demand for, and pricing of, the new shares offered – the opposite result of that sought by the issuing management. To date, mechanisms to prevent issuing firms from managing earnings opportunistically are non-existent. I address this current gap in the literature by proposing a disclosure-based framework for issuing firms aimed at reducing the extent of information asymmetry between them, outside investors and underwriters. Specifically, I present a mechanism where firms add a voluntary “honest disclosure” section in their issue prospectuses, in which they provide information that reduces uncertainty about their financial reports. I demonstrate that such voluntary disclosures by firms create a reality that encourages truthful reporting around the offering and results in a more effective capital market. The proposed framework does not require a change in current institutional mechanisms. Furthermore, as an integral part of the prospectus, the SEC will scrutinize the disclosure. Last but not least, the new section should not add significant cost to the issuer.

The dark side of cross-listing: A new perspective from China

Abstract The overwhelming majority of Chinese firms that list their stock both in China and abroad had gone public, and listed, abroad first. We find that when companies listed abroad return to China to issue stock and list, they experience poorer post-issuance stock and operating performance in comparison to purely domestic issuers. Also, they raise more funds relative to their sales, leave less money on the table for investors, and incur lower direct flotation costs. Among returning firms, those which raise higher proceeds relative to sales experience poorer long-run stock performance and lower Tobin’s q post issuance. Our results offer a new perspective on cross-listing, which we term ‘dressing-up-for-premium’. Firms from less-developed markets take advantage of the enhanced visibility and prestige associated with the foreign listing to issue shares domestically at inflated prices and favorable terms, and to raise greater proceeds than they can efficiently use.