Patent Application
20140141246
The present invention patent with title aforementioned and object of description and claims in this cartouche is an inventive solution that has distinguished benefit in the industrial sector of providing calcium carbonate input, as well as it has particular benefit when it aims at the cellulose manufacturing industry, with a wide spectrum of application, especially in the production stage called caustification (CAO+NA2CO3+NA2S+H2O→CACO3+NAOH+WATER) that offers as the final product soda (NaOH) associated with precipitated calcium carbonate and also residual byproduct in the form of CaCO3.
In addition, the novel process allows obtaining CaCO3 from the slurry waste generated in the cellulose industry provided with economic value, which guaranties the same an industrial applicability extensive to industries of paints, ceramics, rubber, steel, plastic, paper and cellulose, among others.
Given that the cellulose manufacturing industry brings with it the generation of a byproduct in the form of precipitated CaCO3, i.e., a residual byproduct requires an emerging demand in the cellulose manufacturing industry to find a solution of handling the same, preferably a solution that adds economic value to said byproduct, in such a way that it ceases to be merely subject to discharge to the environment.
In addition there is an emerging demand from the ecological viewpoint imposing on industry responsible practices for the preservation of the environment, where to do so, especially in the case of the residual byproduct in the form of precipitate CaCO3, it is a fact that it should not simply be dumped into effluent disposed adjacent the industrial plant producing cellulose.
In line with the demand of the invention the applicant idealized the unpublished “system for obtaining precipitated calcium carbonate from calcium carbonate slurry waste; process for calcium carbonate slurry waste recovery, processing and purification and the calcium carbonate product thereof” provided with the novelty associated to the inventive activity because it does not follow so obvious or clear other solutions anticipated in the prior art to use this kind of residual material, where said waste is to be recovered, processed and purified such that the resulting end product becomes a product of economic and ecological interests, adding value in the views of tactical and strategic positioning of the production industry of paper and cellulose.
In addition the “invention” is provided with industrial applicability, being economically viable, given the strictness of the patentability requirements, notably as an invention patent, as provided in the dictates of Articles 8 and 13 of Law 9279.
In order to provide veracity, and consolidate the context mentioned on the topics of introductory framework, an explanation of the state of the art for obtaining cellulose product will be presented, as well as point out the resulting products, both the main product and their byproducts, notably precipitated calcium carbonate, which after critical analysis of the same, once exposed to professionals with expertise in the industry of cellulose production, and also in the processing industry of calcium carbonate, specifically of the type “precipitated”, may identify their limiting aspects, thus consolidating the identification of demand needs generated by use of this byproduct generated from an industrial activity generating large volumes of product and associated waste.
The types of calcium carbonate: they can be thought two distinct types, the first being natural calcium carbonate named “gcc”, and the second being precipitated calcium carbonate (CaCO3 ppt) known as “PCC”.
1. Natural calcium carbonate: it has grids with average particle size from 3.0 μm, and apparent density from 1.70 g/cm3, reaching grids up to 0.5 micron.
2. Precipitated calcium carbonate: it is identified as (CaCO3 ppt), has grids with average particle size from 5 μm, and apparent density from 0.37 g/cm3. In general, the precipitated calcium carbonates have a higher purity and whiteness than the natural ones.
Other versions of the precipitated calcium carbonate (CaCO3 ppt) can reach particles of an average of up to 0.4 microns of a granulometric distribution curve.
The precipitated calcium carbonate (CaCO3 ppt) has characteristics similar to limestone, being alkali, that is, it is a salt with basic characteristics and has a high pH while in aqueous solution. This chemical substance is the result of the reaction of calcium oxide (quicklime) with carbon dioxide according to the following chemical equation:
Ca(OH)2 +CO2 =CaCO3 +H2O
Properties of calcium carbonate: the precipitated calcium carbonate (CaCO3 ppt) can be subdivided into three distinct types according to their physico-chemical properties, and may be extra light, medium and light, respectively.
Among its physicochemical properties it is relevant to note:
The sum of the properties listed above converges to a conclusive one that allows stating that the precipitated calcium carbonate (CaCO3 ppt) is particularly effective as a feedstock in the industries producing paints, ceramics, rubbers, plastics, and mainly in the cellulose and paper industries.
The origin of the calcium carbonate:
a. Natural source: nowadays the calcium carbonate used is derived from mining, notably in ore deposits rich in limestone.
a.1 Process for obtaining calcium carbonate: in the limestone deposits, the calcium carbonate in the form of rock passes through a crushing procedure which reduces the size of rocks, where the amount of calcium carbonate is subjected to lime kilns thus obtaining what is technically called “quicklime—CCP”, which in turn is subjected to a “carbonation” procedure, thereby converging into the precipitated calcium carbonate (CaCO3 ppt) product to be used for broad spectrum of industries.
Commercially, the precipitated calcium carbonate derived from natural sources such as mineral deposits, finds extensive product portfolio as “CARBITAL, HIDROCARB, ITAFILL, ALBACAR, MEGAFILL, ROYALE, CARBOLAG AMONG OTHERS.” All of them are produced by mining and chemical industries from the process described above, ranging from one to another in their chemical and physical properties in accordance with their specific application.
a.2 Problem Identification: although the process of obtaining calcium carbonate in mining meets expectation of production of the same in an economically viable way, it occurs that it demands the need to use working force, which in turn confers high cost coupled with low productivity, thus reflecting the formation of the trading price of the product, which is high and imposes losses to the companies using calcium carbonate as feedstock.
Another problem identified with this process of obtaining precipitated calcium carbonate lies in the fact that it is exploratory in nature, i.e., it requires the extraction activity of calcium carbonate from deposits of calcite, which leads to a predation and degradation action of the region where the deposits mentioned above are located.
b. Calcium carbonate as a byproduct of the cellulose production: cellulose industries use large amounts of caustic soda in their production process, and for this reason they generate part of the soda to be used and, thereby, manufacture their own raw material. The process of generating soda (NaOH) generates waste, primarily Ca-Co3+water, where usually this residue is burned and turned into Cal.
b.1 The production process of cellulose:
understanding the generation origin of the byproduct “calcium carbonate slurry” in the production of cellulose, which comprises the following sequential steps:
b.2 Problem identification: although the residual material in the form of calcium carbonate slurry is burned, it is necessary to have a large scale burning, which brings a restrictive condition to cellulose and paper industries, because they cannot burn all the waste generated, having as a final destination the specific deposits, since they cannot be disposed in conventional deposits due to their high rate of alkalinity; therefore, they could contaminate the groundwater and the soil.
In turn, the byproduct calcium carbonate slurry hitherto has no commercial value added, and has no proper disposal procedure set, being invariably disposed directly into the environment which is now harnessed as an input to correct the soil, and is intended simply to the formation of landfills formed or not adjacent the industrial plant.
The applicant, aware of the economic and ecological gap in the cellulose production industry, notably for its conventional process that generates calcium carbonate slurry as a byproduct (derived specifically from step of caustification—CaO+Na2CO3+H2O→CaCO3+NaOH+water) requires the development of an inventive solution in the form of a system of obtaining precipitated calcium carbonate originated from the calcium carbonate slurry waste itself generated by said cellulose industry, where the system also has defined an novel process involving the collection of said slurry which is taken to sequential procedures of recovery, processing and purification of the byproduct calcium carbonate slurry.
The inventive system is made feasible by specifying an industrial platform specific for the novel process of recovering, processing and purifying calcium carbonate slurry, which in turn can be operated remotely in a specific unit for this purpose, or locally i.e. in the cellulose industry itself, where such a decision will be taken in line with the best logistic equation specific for each case of deployment, such as geographic location, availability of transport routes, freight cost, degree of security saturation of the cellulose industrial plant, among other factors embedded in the science of industrial logistics and or transport.
Along with this novel proposal of system translated as a productive platform, the benefit which converges in solving the problems of economic and ecological order previously listed on the topic art background is established.
Objectives of the inventive system:
The environment protection is enhanced by the relevant fact that this process features a closed cycle system, and therefore does not allow the emission, release of toxic elements in the environment, where both the water removed by drainage and gas from the drying oven, set in the novel process steps are returned and confined in the cycle.
Predominant distinguishing characteristic: in order to make the list of goals listed in the proposed invention feasible, the novel system of obtaining precipitated calcium carbonate originating from calcium carbonate slurry waste was conceived, distinguished by being a closed system where there is the capturing of slurry calcium carbonate byproduct generated in the step of caustification (CAO+NA2CO3+H2O→CACO3+NAOH+water) provided in the cellulose production, which goes through the following modules:
The inventive system ensures that the untreated calcium carbonate slurry, while passing through the operation and process modules, converges into precipitated calcium carbonate with added commercial value.
In turn, each of these modules is operating with predefined, specific steps, each with equalized procedures, making the process of obtaining precipitated calcium carbonate highly productive and with final quality assured.
A complementary to the present description of the specification, in order to obtain a better understanding of the characteristics of the present invention patent, is accompanying the same, with a set of drawings attached, where A complementary to the present description, in order to obtain a better understanding of the operation characteristics of the process accompanying the same, with a set of drawings attached, where so as exemplified, but not limited to, is represented a preferred embodiment for the invention, where:
The following detailed description should be read and interpreted with reference to the block diagrams, process flowcharts and operating platform disclosed, and is not intended to limit the scope of the invention which is limited only to what is explained in the set of claims.
The cellulose production process: as shown in the flowchart of
System to obtain the precipitated calcium carbonate: as evidenced by
Platform to obtain the precipitated calcium carbonate: as evidenced by
The novel process of recovery, processing of the slurry waste with high content of calcium carbonate: consists of the following steps:
The delaminated calcium carbonate slurry has lighter particles, which gives a better performance in its use as end product.
The position of the mills (5) and (6), respectively, can then be modified to beyond the system, depending on the product to be produced. For example, this system provides a material for commercial application known as “Ecofill pl, tt, s”.
In turn, the residual amount retained on the sieve (7) is called “lime waste”, representing approximately 3% on average of the total volume of crude homogenate calcium carbonate product; and this lime waste is removed again from the vibrating sieve (7) and stored in a specific location for subsequent preparation as an input in a form to correct the soil for agriculture;
The gas generated by the boiler (12) by burning the oil is sent via a blower device to the passage tank provided in the step of decanting the slurry (f) in order to always maintain the optimal pH of the product in order not to use chemicals and not emanate the same gas in the air.
Basically, it is in the system and method innovated and claimed that the purification, the control of particle size and the bleaching of particles, and also the morphological control are made, resulting in the precipitation of CaCO3, thus obtaining a valuable product of economic interest.
The resulting product: the precipitated calcium carbonate (CaCO3) brings with it a defined morphological structure and with distribution of controlled particle size, giving the visual feature provided of great smoothness, high brightness, high opacity and bulk, thus ensuring potential use by papermaker industries, in filter and size press which, in order to make the understanding of the physical and chemical properties of the product more believable, table 1 is presented.
The choice of the preferred embodiment of the invention object of claim in the present cartouche, which is described in details in this topic, is provided only by way of example. Alterations, modifications and variations can be made in any other embodiments of the continuous and closed process of recovery, processing and purification of calcium carbonate slurry waste by those with skill in the art, without however departing from the purpose disclosed in the present patent, which is defined solely by the appended claims.
It appears by what has been described and illustrated that the “CONTINUOUS AND CLOSED PROCESS OF RECOVERY, PROCESSING AND PURIFICATION OF CALCIUM CARBONATE SLURRY WASTE IN THE PRODUCTION OF CELLULOSE AND THE CALCIUM CARBONATE PRODUCT THEREOF” claimed here fits the standards governing the invention patent in light of the Industrial Property Law, deserving by the foregoing and as a consequence the respective privilege.
| Number | Date | Country | Kind |
|---|---|---|---|
| SP018110022266 | May 2011 | BR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/BR2011/000475 | 12/15/2011 | WO | 00 | 11/14/2013 |
