An efficient method of determining the quartz content in feldspar ceramic raw material

1959 ◽  
Vol 16 (4) ◽  
pp. 222-224
Author(s):  
S. M. Kupfer
2020 ◽  
Author(s):  
Franco Rodeghiero ◽  
Cavallo Alessandro ◽  
Giovanna Antonella Dino

<p>The Monte Bracco area (western Alps, northern Italy) is well known for the “Bargiolina” quartzite, a dimension stone that has been exploited in slabs at least since the XIII century, used as internal and external facing, especially in the Baroque. The quarries are located mainly on the top of the Monte Bracco, geologically pertaining to the Dora-Maira Massif, a crystalline massif of the Penninic Domain (Palaeozoic basement and a thin Mesozoic cover). The quartzites occur in sub-parallel lenses (thickness between 2 and 10 m), hosted by ortho- and paragneiss, locally strongly altered in clayey material (kaolinization). The quartzite varieties are characterized by a fine and homeoblastic grain size, a granular – lepidoblastic texture, with regular spaced schistosity, and the main rock-forming minerals are quartz (70 – 90 wt.%), phengite (up to 15 wt.%), K-feldspar (orthoclase, 5 – 10 wt.%, frequently altered in kaolinite) and traces of albite, chlorite and accessory minerals. The quarrying activity boomed between the XIX and the end of the XX century (up to 40 quarries), but the bad exploitation planning in the XX century, which involved the best portions of the rock body, led to partly exploited quarry benches, characterized by a residual yield rate of about 4-8%. At present the quarrying activity is nearly stopped due to low yield rate (and the consequent huge production of waste) and to the competition of the widespread “golden quartzite” from Brazil. The huge amount of quarry waste, the quartz-rich composition and the abundance of kaolin in the altered host gneiss suggest interesting applications as industrial minerals. Due to the high quartz content, the quarry waste (estimated in 2,250,000 m<sup>3</sup>) could be extracted as a secondary raw material and mineral dressed to obtain products for ceramics, refractories, abrasives and glass manufacturing. The recovery of the kaolinized host gneisses should also be evaluated: the deposit shows proper geochemical, mineralogical and petrographical characteristics for kaolin exploitation, which however should be programmed and carried out together with the exploitation of the quartzite deposit (which lays on the kaolinitic gneiss bench). Preliminary mineralogical and geochemical data (XRPD and XRF) show an appreciable amount of kaolin (8 – 25 wt. %, with a very low Fe<sub>2</sub>O<sub>3</sub> content) in the altered gneisses, and a substantial compositional homogeneity in the different sampled areas. In addition to kaolin, the other main minerals are quartz, K-feldspar and a mixture of phengite and illite, a quite good “raw material” for the ceramic industry. The volume of the kaolinitic gneisses should be further evaluated by targeted field and geophysical surveys, followed by core drilling. In the perspective of a sustainable mining, it is important to move towards the integrated exploitation of the Monte Bracco area, contemporary mining both the quartzite waste and the kaolinitic gneiss (first category materials, industrial minerals), as well as the quartzite benches (second category materials, dimension stone).</p>


Refractories ◽  
1973 ◽  
Vol 14 (11-12) ◽  
pp. 773-775
Author(s):  
Yu. P. Dyban' ◽  
�. K. Keler
Keyword(s):  

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 486 ◽  
Author(s):  
Shangde Sun ◽  
Jingjing Guo

Ricinoleic acid (RA) is an important raw material for plasticizers, emulsifiers, and nanomaterials. In this work, a green and efficient method was developed for RA production. Results showed that Lipozyme TLIM can be used as a novel biocatalyst to catalyze the hydrolysis of castor oil (CO) for RA preparation. Response surface methodology (RSM) was used to evaluate and optimize the effects of reaction variables on the hydrolysis of CO. Reaction conditions were optimized as follows: 41.3 °C, enzyme load 8.9%, 39.2 h, and 40:1 molar ratio of water to oil. Under these optimized reaction variables, the maximum hydrolysis ratio of CO (96.2 ± 1.5%) was obtained. The effect of hydrolysis variables on the reaction was as follows: enzyme load > hydrolysis time > temperature. In conclusion, this is a green, simple, and efficient method for RA preparation and can provide a good alternative method for RA industrial production.


2007 ◽  
Vol 344 ◽  
pp. 921-927 ◽  
Author(s):  
Ernesto Lo Valvo ◽  
Roberto Licari

The nesting of two-dimensional irregular shapes is a common problem which is frequently encountered by a number of industries where raw material has to be, as economically as possible, cut from a given stock sheet. A frequently recurring problem as far as cutting stock is concerned, is how to obtain the best nesting of some pieces of flat patterns which occupy minimalarea convex enclosure. The area of convex enclosure is related to the convex hull of the union of patterns which can be imagined as a large rubber band surrounding the set of all polygons. Our goal is to automatically obtain the smallest area convex shape containing all the patterns. As a matter of fact, Cheng and Rao have proposed an heuristic “stringy effect” procedure for clustering which follows a descending order of area of patterns. The “stringy effect” is able to put each new piece in a position which minimises the value of the distance between the centroid of each added piece and the centroid of the already formed cluster. The procedures till now shown in literature are quite complex. They make use of sliding techniques, and are not able to effectively work with relatively multiply-connected figures. In particular, the different procedures proposed are based on the No Fit Polygon computation of non-convex polygons, which often generates holes. This work is a proposal for a more efficient method, which can be used in heuristic procedure. In this paper a new procedure for the calculation of “No Fit Polygon” (NFP) of non-convex polygons is presented. Given two non-convex polygons, the algorithm is able to calculate their NFP very quickly and without any approximation by a polygon clipping method. By iterating this procedure with every polygon of our set, and positioning them using the “stringy effect” technique, it is so possible to obtain a convex shape that contains all the patterns, having the minimal area.


2018 ◽  
Vol 912 ◽  
pp. 55-59
Author(s):  
Lucas Fonseca Amaral ◽  
Carlos Maurício Fontes Vieira ◽  
G.C.G. Delaqua ◽  
M. Nicolite

In this study the objective was to evaluate the properties affected by the incorporation of phyllite and sand as raw materials in the composition of ceramic material for the roofing tiles production with light color using kaolinite clay from Campos dos Goytacazes – RJ, Brazil as main raw material. Specimens were prepared by uniaxial pressing at 20 MPa and fired at 950oC. The determined technological properties were: dry apparent density, linear shrinkage, water absorption and mechanical strength (three point bend test). The results indicated that the incorporation of sand and phyllite improved the dry apparent density, reduced loss on ignition and aluminum oxide content of the pure clay. These factors resulted in a reduced open porosity, improving water absorption and linear shrinkage. However, the mechanical strength was compromised due to the increase of quartz content.


2001 ◽  
Vol 60 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Lucia Savadori ◽  
Eraldo Nicotra ◽  
Rino Rumiati ◽  
Roberto Tamborini

The content and structure of mental representation of economic crises were studied and the flexibility of the structure in different social contexts was tested. Italian and Swiss samples (Total N = 98) were compared with respect to their judgments as to how a series of concrete examples of events representing abstract indicators were relevant symptoms of economic crisis. Mental representations were derived using a cluster procedure. Results showed that the relevance of the indicators varied as a function of national context. The growth of unemployment was judged to be by far the most important symptom of an economic crisis but the Swiss sample judged bankruptcies as more symptomatic than Italians who considered inflation, raw material prices and external accounts to be more relevant. A different clustering structure was found for the two samples: the locations of unemployment and gross domestic production indicators were the main differences in representations.


2006 ◽  
Vol 103 (2) ◽  
pp. 76-81
Author(s):  
C. Perin Filho ◽  
D. Tassinari Miranda ◽  
E. Medeiros Milanez ◽  
E. Luiz Massanori Harano ◽  
E. Torres Bispo dos Santos ◽  
...  

Metrologiya ◽  
2020 ◽  
pp. 38-51
Author(s):  
V. N. Astapov ◽  
I. N. Kozlova

This article presents the rationale and methodology for developing an intrinsically safe device, namely, a hydrostatic fiber optic sensor with a position-sensitive detector for monitoring the level of oil products in large-capacity tanks at oil depots and during pumping in a raw material warehouses. This device suitable for continuous monitoring of the liquid level, based on the measurement of a hydrostatic column of liquid with automatic offset of changes in the density of the liquid. Offset is carried out by means of a displacer (a fully submerged float), inside which a housing with a position-sensitive detector (PSD) is integrated. Theoretical validation of the bellows suspension usage for a displacer is given. During filling a container with a liquid whose level is measured, liquid bellows, the movement of which is recorded by an optical triangulation sensor using the reflected infrared ray incident on the bottom of the bellows. The principle of the triangulation sensor operation is based on the geometric properties of the triangles. The pulses of infrared radiation come through a fiber optic cable. In order to measure the movement of the surface (the bottom of the bellows) by measuring the movement of the reflected beam, a position-sensitive detector is used, which is located in a remote controller. In this device for the intrinsic safety problem solution, optical inputs of a fiber optic flat cable are located in the active zone of the sensor, which is connected to the optical inputs of a position-sensitive detector, operated on the principles of photoelectric effect. The light spot moving along the sensitive zone and converted by the detector into a one-dimensional signal proportional to the distance to the object. hydrostatically applies pressure over the entire effective area of the measuring


2016 ◽  
Vol 2 (4) ◽  
pp. 234-241
Author(s):  
Mohammed Al-Shakka ◽  
Ebtesam Abood ◽  
Adel Al-Dhubhany ◽  
Sami Abdo Radman Aldubai ◽  
Khaled Said ◽  
...  

Because of the almost-instant connection with the welfare and well-being of individuals, pharmaceutical industry stands prominently as a very important factor for the improvement and progress of a healthy productive nation. These days, pharmaceutical industry thrives as one of the largest and exponentially expanding global industries. Nonetheless, millions of people in low income developing countries, have to suffer from the fatal consequences of the inaccessibility and non-availability of essential drugs. This is also happening in Yemen, where the pharmaceutical manufacturers sector have to face up to many challenges. The Yemen Drug Company (YEDCO) was founded in 1964 by the Yemeni government as it collaborated with private investors. It was endorsed as a company with the expertise in the medicinal drug marketing. YEDCO started its work by taking in drugs from foreign companies and then locally marketing and distributing them. In 1982, YEDCO built the first medicinal factory for drugs in Sana’a. Since then, seven companies were set up to manufacture medicines in Yemen. The expanding population has led to the need to have more pharmaceutical products. It may be understandable that pharmaceutical manufacturer companies are also hit by the political crisis in the country. Inadequate amount of fuel and raw material as well as low security status were some of the underlying factors behind these ill-effects in Yemen. Imported drugs make up about nearly 90% % of the pharmaceutical market compared to 10% drugs from the domestic market. This situation has led to an additional burden being shouldered by the national economy, where Yemen spends about US$263 million annually on pharmaceutical drugs, in reference to the national Supreme Drugs Authority. Although there is a very quick growth in the population and drugs consumption, the pharmaceutical industry has not been very active, where global pharmaceutical products play their role dominantly on the domestic market. The pharmaceutical production necessitates skilled human resources like university graduates. By contrast, the government and the private sector should also motivate the pharmaceutical industry and make use of the local employment


Sign in / Sign up

Export Citation Format

Share Document